Trust me on this, but BioWare is not going to lose major support over just Mass Effect 3. That is like saying Blizzard is in dire straits for the ruckus about Diablo 3. You have players loving and hating either game, both companies earning money, and both companies have an outstanding track record of producing successful games.
BioWare could spend 1 billion dollars creating Minesweeper: The RPG for all I care, and I would still try their games. It is a bit hard to comprehend, I am sure, but I've been loyal to BioWare since Baldur's Gate and they've NEVER failed me. Yes, there have been some disappointments (Awakening, DA2), but there has never been a BioWare game that has made me so horribly disillusioned that I'd say "I have to stop playing this game, right now. This is awful, I can not continue, even if I haven't finished it". I still found parts about Awakening and DA2 (which are the games I don't like too much out of the ones BioWare made) to be really great, and they worked very well. Those two, while not epic, were still good games (although DA2 was in danger of getting into "mediocre" with its story and reused areas).