Each map in-game has a feature called 'levolution' where a huge set piece on the map is broken or blown up and it creates massive destruction and changes to the map. There are also minor versions of this around each map as well.
Paracel Storm has a warship stuck to an offshore wind turbine, which if blown up, results in the ship breaking free and crashing onto an island and destroying a large building.
Siege Of Shanghai allows the players to blow up the large skyscraper in the middle of the map and causing it to collapse. There is also a part of the map that is an underground shopping center, but if you blow up a support pillar, it results in the road above collapsing, which can drop vehicles or players through the hole.
There is a map set at the Arecibo Observatory where you can cause the central structure of the telescope to break and collapse.
Caspian Border keeps the same radio tower destruction from Battlefield 3.
One of the Chinese maps allows you to flood a city to create a watery urban battlespace.
They added the ability to counter someone knifing you, resulting in you stabbing them with their OWN knife.
Tombstone in general in the campaign. The first few missions has them surviving against long odds, but once they get captured, everything goes off the rails. They break out of a prison camp, slaughtering the guards, wander through the snowy mountains for days with no food, supplies or cold weather gear, attack a Russian formation and succeed despite exhaustion, and blow up a dam to take out the Russian forces, something that the Marines that had been stationed in the area for days were singularly unable to do. And then, they parachute onto their own under-attack-ship, fend off a concentrated Chinese assault, and blow up an enemy ship with C4 (or not) to save their own ship. In the course of 4 days, they probably caused more destruction and confusion to the Chinese forces than the rest of the US force combined.