Resident Evil 5's PC edition has fully transitioned to Steamworks support, Capcom has announced, but any DLC bought previously will not transfer with it.
Update 3/31: Capcom has now amended its original post to note that there was no downloadable content offered with the original Games For Windows Live version of the game, mooting this particular issue. The Gold Edition of Resident Evil 5 offers the DLC at $15.99 for anyone with a previous GFWL version of the game.
What this means is, anyone who bought the game (its original launch was 2009) on Steam can upgrade automatically to the full Steamworks edition, free of charge. No more using Games For Windows Live, the much despised DRM and online gaming service whose demise has been frequently rumored. The code used on physical copies of Resident Evil 5 for PC will also activate the Steamworks-enabled code.
However, any downloadable content bought from the Games for Windows Live Marketplace does not transfer, as it doesn't have a CD or activation key.
The original GFWL version of Resident Evil 5 still works, is still supported, everything.
Save files also will be transferrable, but Capcom says that the save data and achievement migration tool for Resident Evil 5 will be "ready after launch," and that users should look to the game's official Steam forum for an announcement when it does.
For those who might be buying the game new, the Steamworks version includes all of the Gold Edition content for Resident Evil 5's Xbox 360 and PlayStation 3 versions.