The following is from the official press release:
The Mass Effect trilogy is a masterful science fiction adventure set in a vast universe filled with dangerous alien life forms and mysterious uncharted planets. In this dark second chapter, Saren's evil army of Geth soldiers has just been defeated, and humans, who are still struggling to make their mark on the galactic stage, are now faced with an even greater peril…Speculation after Electronic Arts acquired BioWare led many gamers to believe that the Mass Effect franchise would be coming to Sony's PlayStation 3, yet nothing has been announced thus far. Contractual obligations related to a pre-existing deal with Microsoft are the likely cause.
"We're going to surpass the extraordinary gaming experience we brought our fans in Mass Effect by delivering intensified combat and expanded weapon options as well as increased depth of planet exploration, all while delivering a powerful, emotionally engaging story," said Dr. Ray Muzyka, General Manager and CEO, BioWare and General Manager and Vice President, EA. "Mass Effect 2 is shaping up to be an unforgettable RPG-shooter experience, taking players on a non-stop roller-coaster ride filled with stunning plot twists and no-holds-barred action."


PC gamers, on the other hand, are likely pleased at the prospect of what should be a simultaneous release for Xbox 360 and PC.
Early 2010 may seem fairly far away, but it makes perfect sense from a timing perspective. BioWare's Dragon Age: Origins is slated for release in Q4 of this year, and the company is unlikely to want to release competing products so closely together. The perfect timing would have gamers picking up Dragon Age: Origins this holiday, playing through it, and then buying Mass Effect 2 in the coming new year. Once those are done, the anticipation for Star Wars: The Old Republic can begin in earnest.
We're fans of Mass Effect here at GameSpy HQ, and have offered our unsolicited suggestions for what would make Mass Effect 2 a better experience.