The new combat system for dragons allows you to attack their limbs, much like Dragon's Dogma. The demo at E3 shows how taking out a leg causes the dragon to roar pitifully and start limping. The developers wanted to convey that while dragons are a vicious menace to society, they are still living creatures.
After killing Alexius, Dorian laments that a man who he used to greatly admire became so twisted.
Amazon Brigade: A female Inquisitor plus Cassandra, Vivienne and Sera.
Anti-Magical Faction: The purpose of the original Inquisition, before it joined forces with the Chantry and became the Templars and Seekers of Truth. What path the new Inquisition follows depends on your choices (and the first brand-new companion announced is a mage advocate, although one that previously supported the Chantry and the Circle system before the Templar-Mage war broke out).
Beef Gate: Though areas are open, most enemies won't scale to your level, making it hard to access a sub-region if you can't beat the monsters inhabiting it.
Benevolent Architecture: Thanks to the shift to the Frostbite engine, Inquisition now features destructible environments. This includes things like knocking out the supports of a bridge, causing it to collapse from under the archers standing on it, toppling pillars to create cover from ranged enemy attacks, or destroying cover the enemies themselves are using. Presumably, though, it can go the other way, and not all architecture is destructible.
Big Bad: Whoever is responsible for the tear in the Veil, which if Alexius is to be believed is known as the "Elder One".
Body Horror: Some of the Red Templars have been mutated by their use of Red Lyrium. These mutations range from having red lyrium protruding from them to becoming a behemoth that is barely recognizable as having once been human.
Bonus Boss: Most dragons are endgame-level encounters and are not needed to complete the game, but killing dragons allows the player to get the best crafting materials in the game.
Boss Banter: Alexius taunts the Inquisition throughout his fight.
Broken Bridge: You won't be able to access an enemy castle, for example, unless you've first recruited enough forces through quests to lay siege.
Bullet Time: Haste, a Focus spell for mages, slows down time for you enemies while allowing your squad to move normally.
Call Back: The Temple of Sacred Ashes from the first game returns as the site of a major peace summit. The Breach opens right on top of it.
Chain Pain: Warriors now have the option to yank opponents towards them using chains.
A wide variety of ornate or otherwise nifty looking one and two handed swords are available for your party to find.
The Red Templars wield glowing red swords that bear a disturbing resemblance to Meredith's red lyrium sword from the previous game. The Red Templar Archers also get similar looking bows, which bear a slight resemblance to Irvine's demonic one from Berserk.
The Conspiracy: The Inquisition is resurrected to get to the bottom of claims a shadowy conspiracy is behind the political strife preceding Inquisition's demonic invasion.
Crapsack World: A cataclysmic event has plunged the entire continent into turmoil, dragons are darkening the skies, and the Mage-Templar War is now just one of many wars that have claimed countless lives.
The World Is Just Awesome: Yet, in spite of all of that, one of the trailers has this from the Inquisitor to the audience, saying that the Inquisition's mission will have them traveling across the lands to many different places, both beautiful, dangerous, ancient, while showing images of various beautiful places to show the audience that yes, for all of the darkness and cynicism in the series, there are things in Thedas that are worth saving.
Defector from Decadence: Dorian leaves the Tevinter Imperium due to disillusionment with his country's moral decay (The Imperium is known and criticized for practicing slavery and values greed as an admirable trait).
Deployable Cover: New spells create a walls of ice and fire that your party can hide behind.
Guilt-Based Gaming: A Bioware tradition. The first gameplay demo shows the Inquisitor deciding whether their soldiers should stay with the wounded, protect the nearby village of Crestwood, or push an assault on the attacking Red Templars. The Inquisitor picks the last one - and Crestwood is burned to the ground by the time they return.
Hell Gate: The Breach; a tear in the Veil that separates the Fade and the mundane realm, opens in the sky, allowing demons and other monstrosities to invade.
Helmets Are Hardly Heroic: Like in the previous game, there is an option to make the headgear worn by the Inquisitor invisible to better show off the player's personal face customization. Played with similarly to the last game in that the helmet's stats and defense still apply, meaning the player will still want to wear a helmet at all times.
Nay-Theist: According to Bioware, the restored Inqusition is strictly separate from the Chantry and will even have some anti-Chantry policies.
Neck Snap: Leliana uses her legs to break the neck of a Venatori who was torturing her.
Never Heard That One Before: The devs managed to inflict this on themselves re: 'Spanish Inquisition' jokes, and resolved not to include any in the actual game.
Nice Hat: Apart from the Inquisitor's signature helmets, it seems that absolutely badass cowboy hats will also be equippable. Vivienne has a Maleficent-style horned hat (a welcome change from previous mage headgear).
Nostalgia Level: Redcliffe Castle gets taken over by the Venatori and, like in Origins, you are tasked with reclaiming it.
Old Save Bonus: All previous world-states will be imported to the game through the "Dragon Age Keep", a web application that will allow players to replicate old save states and generate new ones.
The Order: The Inquisition, an organization formed to restore order and root out conspiracy.
Order Reborn: The original Inquisition was disbanded nearly a thousand years ago.
Party in My Pocket: Party members disappear when the Inquisitor is mounted and re-appear when the Inquisitor dismounts.
Party of Representatives: The party members embody different viewpoints and have differing levels of investment in certain issues, as discussed here.
Playable Epilogue: You can continue to explore the world after you complete the main questline.
Player Headquarters: The Inquisition's headquarters, Skyhold, is a central area where the player can speak to their companions, similar to the party camp in Origins. The fortress is also customizable to some degree, similar to Admiral Anderson's apartment on the Citadel in ME3. The Inquisition gains other fortresses as the story progresses.
Player Party: As in the previous titles, you can switch control to any member of your current party at will.
Point-and-Click Map: Unlike in the previous games, you can travel quickly between known places even on the local map of the area, simply by selecting your destination—which is probably due to the sheer size of outdoor levels.
The Power of Friendship: Focus is a resource that is built up in combat through teamwork and allows the party to use powerful abilities such as slowing down time for their enemies.
Powerup Mount: You can now ride horses to get around areas faster.
Pre-Order Bonus: The Flames of the Inquisition DLC, which includes weapons, gear and an armoured horse.
For party members, some pieces of their wardrobe always remain the same, like Cassandra's trenchcoat-like garments.
For the Inquisitor (and everyone else), a new crafting system allows you to produce replicas of equipment you already own from the materials (and thus colors) you prefer but with the same stats.
Romance Sidequest: Various romance options for your main character are available, as in the previous games. Indeed, developers have confirmed eight love interests, more romance options than any previous Dragon Age game. Thus far, Cassandra and Cullen have been confirmed as straight, Josephine and the Iron Bull have been confirmed as bisexual, and Sera and Dorian have been confirmed as gay.
Shield-Bearing Mook: In the same vein as the Cerberus Guardians in ME3. This emphasizes party teamwork - you can't punch through the shields even with magic, so you need to flank or disarm them.
Shoddy Knockoff Product: In-Universe; Word of Godsays that "Hard in Hightown 2", the book next to Cassandra's maps, is an unauthorized sequel to Varric's original. The book had previously appeared in Varric's companion specific sidequest in Mark of the Assassin, where he was furious to discover someone ripping off his work, leading him to collect all the copies he could find at Chateau Haine so he could burn them.
The Smurfette Principle: Female party members are outnumbered two-to-one. The ratio is a little less steep if you include the advisers.
Stopped Numbering Sequels: Originally announced as Dragon Age III: Inquisition, the III was eventually dropped from the title, due to the transition to next generation consoles. Plus, DAIIII as abbreviation probably would have been awkward.
War for Fun and Profit: The Hidden Villain is deliberately prolonging the various wars for their own benefit. Case in point, the Breach opens right on top of a peace summit for the Mage-Templar War.
War Is Hell: Many characters are scarred by the events of the civil war. The first trailer shows the world on the verge of collapse, with a shell-shocked Varric standing amidst a field of dead in Crestwood.
The War Room: Skyhold has one, complete with war table. The war table allows you to manage the Inquisition's operations: side quests that you sent your agents to take care of.
The War Sequence: One region is so thoroughly under enemy control that you have to send in your army to deal with it.