With Xbox 360 title Mass Effect coming to PCs this May, logic tells that Mass Effect 2 is going to eventually hit PCs. That's common sense! But when? Matt Atwood from developer BioWare says:
We haven't announced plans for timing on Mass Effect 2, period, so at this point we're not really ready to talk about it, but because we've got a really great PC fan base we think it's really important to deliver the PC experience as quickly as possible. Look for more news on that soon.
Okay. We will.
Mass Effect Confirmed for PC [videogamer.com]