[quote name='Saix_XIII']To call it an expansion would be to call ANY game with a sequel that uses the same engine an expansion. Mass Effect, Assassin's Creed, Gears of War, Halo, etc etc etc. They expand on the story/gameplay, that is true. But expansion means it requires the base game to function properly. This game does not. The WoW stuff are expansions, Brood War is an expansion.[/QUOTE]
Expansions don't always require the base games. "Stand alone expansions" have been around for well over a decade; Kohan Immortal Kings, Half-life Blue Shift, Dawn of War 2 Retribution, Supreme Commander Forged Alliance, Half-life 2 Episode 1/2, etc. Even then, Blizzard stated earlier that Heart of the Swarm would require Wings of Liberty to play anyway.
I don't see why this is such a big deal to people. It's an expansion by any definition (including Blizzard's), but that doesn't change anything about the game itself. It's good it's an expansion though, since that means it should be cheaper than a full sequel would be. I'm definitely hoping that $39.99 is the actual retail price, but considering that Blizzard's full games recently have been $10 more than their previous ones (Starcraft 2 Wings of Liberty and Diablo 3), I wouldn't have been surprised if they tried to get $49.99 for it.