We know nothing of the actual combat mechanics. In fact, we know nothing of the advancement system, either. And as it turns out, BioWare stealthily revealed their multiplayer dialogue feature at E3 but didn't want to delve into any specifics – even while gushing about their massive voice-over efforts. Everything has been about macro-features – none of the middle ground or micro stuff such as the aforementioned combat mechanics or advancement. Seems a bit strange.
If holiday 2010 was the prime release window, we would -- at a minimum -- know some specific core MMO features. Heck, nobody even has a clue as to whether or not BioWare plans on enacting the "Holy Trinity" approach to group dynamics, let alone what Jedi variations players can select. Truthfully, a lot of this game appears to be evolutionary, and the voice work is undoubtedly revolutionary at least in vision. As much as I'd love for the game to release in late 2010, the scope of this its design, funding and third-party involvement alter the odds to such a low percentage that, were it to occur, would astound me more than SWTOR's actual existence.
That may sound like quite the resounding final statement, but there's a bit more to this topic: Blizzard.
BioWare, Electronic Arts and LucasArts are fully aware of the competition. Everyone has to be; this is a business after all. When fighting an opponent, a winning blow depends on timing as much as it does strength or skill. You can bet your blood that everyone over at camp SWTOR is aware of an impending third World of Warcraft expansion (likely to land sometime in 2011) and the much bigger threat – Blizzard's sophomore effort. Obviously, their second MMO isn't happening for a while. I mention it because of SWTOR's first expansion – the sooner the game is released, the sooner its first, ever-so-tempting expansion can come out as well.
So, while I may say holiday 2010 is a unlikely, I'm not foolish enough to assume it's wholly impossible. BioWare may be "okay" to launch late next year, and they may do so if Blizzard is on top of their game. However, we should remember that competition goes both ways, and trying to imagine the amount of money Activision-Blizzard is pumping into expansions and that follow-up MMO is gut-pumpingly sickening.
Got away from myself there, but you get the point. This game could be huge, or it could just be pretty big, and it could all teeter on the timing. The worst case scenario has been seen before, so there's no need to illustrate it. Just don't be too upset if you don't get your SWTOR on next year.