According to the announcement and the FAQ posted on the Bioware's forum, it looks like there will be no harsh DRM for Mass Effect. During the past week Bioware announced that the PC edition of Mass Effect will have online activation every 10 days, which didn't really go well with the fans. Hearing their displeasure, Bioware has decided to drop these DRM plans.
The game will still have online activation, but this time it will only be one time, and reactivation will be only be required when new content has been downloaded.
It still has the limit of just three computers, or three authentications, as they like to call it, but it will be possible to get additional authorizations if they are warranted.
According to the post over at Kotaku, EA is going the same way with its upcoming Spore game. You can check out the Mass Effect forum here, and the Spore details can be found here.
Mass Effect and Spore with online activation