Currently only coming to Xbox 360 and PS3.
Last week Capcom announced a series of DLC releases for Resident Evil 5, bringing two new episodes, new character costumes and an enhanced Mercenaries Mode to players of the Xbox 360 and PS3 versions of the game.
Despite showing strong support for the PC, Capcom made no mention of the DLC being made available for the Games for Windows edition.
G4's The Feed asked Capcom for clarification, to which a spokesperson responded: "No plans for PC at this point."
It looks like PC Resident Evil 5 fans are out of luck. You'll have to make do with 3D support and the ability to play the game in high resolutions.