Ascended Fanon: When the Widow Mine was turned from an actual mine into a missile-shooting Area Denial Weapons System, many of the beta testers asked its name to be changed due to it becoming a Non-Indicative Name. While the actual unit name couldn't be changed for multiple reasons, the name "Sentinel" was thrown around the forums a lot, so its weapon name was changed from "Unstable Payload" to "Sentinel Missiles" as a compromise.
Some people like referring to Rory Swann as a "Space Dwarf" since he's short, stocky, bearded and good with machines. He does spend all his time in Bay 12. No Scottish accent, though.
Watching commentary replays of pro-level games requires learning an entire fan vocabulary of names for the different build orders and strategies used, especially since several terms sound similar but have different meanings, such as six-poolnote A Zerg player creates a spawning pool with his sixth drone, 4-gatenote A Protoss player builds four gateways before focusing on anything else, regardless of worker count, and one-one-onenote A Terran player builds one Barracks, one Factory, and one Starport, racing up the Tech Tree to air units as fast as possible. Occasionally called the Destiny Cloudfist Build by Husky Starcraft fans..
Courtenay Taylor (Jack, Juhani) is Lassara and Niadra.
Irony As They Are Cast: Mengsk's voice actor (James Harper) is friends with Tosh's voice actor, (Dave Fennoy) whereas in the game, they hate each other.
No Export for You: The jukebox has some pretty awesome tunes. Too bad you can't have it on your MP3 player if you live in the two-thirds of the world where iTunes doesn't sell music tho. And to drive the insult home, even if you have successfully ripped the music out of the game files, you still won't have the extra tracks only available on the digital album. Plus, the files have been filtered to sound as if it's being played on a jukebox (complete with vinyl crackles) so it won't be satisfactory to listen from an MP3 player
Kerrigan's change is somewhat bittersweet. While her original VA, Glynnis Talken Campbell, is adored by StarCraft fans, her new VA is universally nerd-approved Tricia Helfer. They go so far as to redo several of Kerrigan's lines from a pivotal moment in the first game with the new VA, so at least they didn't half-ass it.
Saved from Development Hell: A case of a character being rescued from development hell. Like Thrall (from Warcraft) before her, Nova was supposed to be in a game (Starcraft: Ghost) that was never released, but got included in the main franchise anyway.
Throw It In: The strange glowy hexagons on some of the fields were at one point a testing pattern, possibly used to test movement and cell selection. During play testing, someone thought they looked neat, so they decided to keep them.
Early footage of the single-player campaign hinted at a subplot of the Hyperion crew considering a mutiny due to being underpaid and overworked. There is a similar subplot in the final product, but the motivation for the crew is not working conditions, it's Jim's decision to work with the Dominion to defeat/rescue Kerrigan. The same footage showed you could return to Mar Sara for a mission later in the game. This was also scrapped.
Kachinsky was originally planned to be another main character with his own set of missions to provide.
At some point Donny was planned to be killed by riots during the uprising on Korhal after "Media Blitz". He would then have been revealed to have been a robot. Though this plot element was scrapped, his sparking half-destroyed robotic body is still in the map editor.
All over the place with units, who had abilities constantly shifting around during development. To list what would be some of the more influential changes:
The Viking would have been built from the Factory with the air mode transformation as an upgrade. Around this time there was a different Terran ATA unit, the Predator.
The Queen would have evolved along with the player's Hatchery, gaining more HP, power and stronger abilities as it evolved.
The Carrier would have been replaced by the Tempest, a weaker anti-ground focused unit, and the Void Ray, then the Warp Ray, was the new Protoss capital ship.