According to a post on the official Steam forums, It appears Capcom is in talks with Valve to put some of their upcoming games on Steam. Little is known about this, however it would likely mean that Resident Evil 4 would be a prime candidate for the platform. More news on this as it comes our way.
Personally this comes as nice news to me, as I'm already a Steam user and have been since its inception. Hopefully this will bring the world of Resident Evil to a broader audience and thus fuel more demand for PC centric games from Capcom.
Update: It appears that they have removed the comment from the podcast. Anyone commenting on it on their website is getting the comments deleted, so it seems this is the real deal! I've checked the audio file myself and its fairly obvious an edit was placed in at the 48 second mark. The interviewer also mentions "dealS" but only lists one company in the edited version.