And, crazy as it may sounds, perhaps they WERE going to release it December 3rd and ran into some technical glitches they knew they wouldn't have fixed by then? Case in point, two glitches found in the E for All demo: the Metaknight 999% damage glitch that happened a few times (there's a video in the E for All video thread that actually has this glitch recorded) and, from what I heard, the Giga Bowser freeze glitch that caused the game to freeze if Giga Bowser was taunting right before he reverted to regular Bowser.
That is the most logical answer. Well, that they were trying to fix technical difficulties, like bugs, glitches, online issues (I hope with this extra month and a half, they fix the online lagging thing in the wi-fi dojo update), and refining characters/stages. Mostly just technical difficulties probably though.
Even then, I'd much rather get the game February 10th, absolutely perfect for me to enjoy for years to come, instead of getting it December 3rd, and having a long list of technical issues that kills the fun for me, and/or the characters not being as balanced as they could be. *COUGH*
WARHAWK*COUGH*
If they push it back how long before the updates tell us everything about the game? Will they stop them? Or maybe we'll get updates like "Now you can still press and hold B to exit menus !"
Brawl is significantly larger than Melee, and they still have more characters, stages, game modes, features, and of course, ITEMS to update us with. We've had barely any item updates. And remember, Sakurai is the master of boring small updates. He could just give us stuff like the "HEY! CRATES SLIDE AROUND!" update for 2 months if he wanted (lol that was the worst update ever -_-)