http://uk.pc.ign.com/articles/879/879239p1.html?RSSwhen2008-06-04_122300&RSSid=879239
It makes perfect sense, XBOX360 games are very easy to convert from PC to 360 and vice versa because of the unified creation process they share thanks to the new standards which is why the latest round of multiplatform games that appear on PC and 360 run the same or run better on PC but mostly look better on PC due to better visuals and resolution (Devil may Cry 4, Mass Effect, GRID etc)
There's absolutely no reason why Res Evil 5 cannot be released on PC given the easyness of the conversion process since it starts out on the PC as a PC game.
They've obviously been marketed and funded for console release first then they will grab the PC gamer's money afterwards. Saints Row 2 is coming to PC too which I very much look forward to and Rockstar will have to release GTA4 on PC because of this since SR2 is a key competitor to taking away some of GTA4 sales.