Yes, Dawn of War is for the PC. It has had 2 expansion packs, and is extremely fun.
The Warhammer Mark of Chaos seems a bit boring to me....I only have the Demo, but some of the levels are just plain snoozefests. If the demo is any indication of how good the game is, I may pass on that.
Blu Ray formatted discs are starting to appear in retail stores now. The real problem is that there are 2 formats that are battling for the High Def DVD market....Blu Ray and HDdvd...each are seperate formats that require their own player. Blu Ray is more expensive, but seems to be a bit higher quality. No one knows which format will become standard, which is confusing the issue now.