EA's also good at the "out before the game is finished" thing thats going around. But Mass Effect is still good, but it does have bugs. Like, especially, with the graphics. Where most things look amazing, most of the clothes and several textures are pretty bad looking in comparison to everything else. But thats not an issue.
Mass Effect 2-3 will be great, its just something you can tell. If you make a great impression with the first game, things will only get better, seeing as they shouldn't need time to render and develope most of the character models(seeing as I don't see the turians, salarians and asari changing much over the time the games take place) and enviroment models will be notably easier to work on, since they have a lot of basic stuff, and just need to add whats necessary. The only daunting part, it would seem, is developing and selling an equal or better story from the first game, which might actually be difficult. The first storyline from Game 1 was amazing. Everything fit perfectly with each clue given, for the most part, and everything ran smooth, so as long as you paid medium attention to what was said, you could learn everything necessary.
The 2nd game will really have to be extrodonary, since Mass Effect definitely won't win the great looking game catagory(I believe that does, and likely will for a while, belong to Crysis, and the sequals) and they did say that Mass Effect "redefined the character and story aspect of video gaming", so Mass Effect 2 will have to really usher out something amazing.
Not only that, but going to an MMO would be, in my mind, a bad move. Most MMO's are stained, not by the game, but by the community. And if the games are any kind of good, they'd be pay to play, which I don't, and likely won't, have the budget to fork out(Though, Mass Effect has a likely large enough fan base to keep it cheap) but like usual, EA would charge more than necessary, for a game thats not finished, and I can't see it being good. I would definitely welcome an MMO, or at least an online aspect. Something along the lines of a TDM, DM, CTF and Co-op element would be a HUGE step in the right direction(Including the create a character aspect, but widened to cover other species.) and could easily thrust Mass Effect beyond just great story telling and characters, gameplay and graphics, and maybe put it as the best RPG-Shooter made.(I'd say it already holds that title, cause I can't think of any better games that fit the RPG-Shooter description.)