Silent Hill: Homecoming will release on PC, in addition to PS3 and Xbox 360. The press release states the game "will be available as a digital download" through Steam and doesn't mention anything about retail.
Meanwhile, there's a report by Darkzero out of Leipzig that the game's release has been delayed from September to November. The press release for the PC announcement, however, still states Homecoming is "expected to launch" in September. We've reached out to Konami to clarify the release date and PC details and will update as soon as we hear something.