I loved Dawn of War II, but I'll also be the first to admit, it's an acquired taste. Might not be for everyone.
So it's handy that Relic have released a demo of the game!
It'll let players still on the fence about the whole thing get a feel for the sweeping changes made to the game, without having to risk their hard-earned, recession-riddled cash. If you like your tactics with a healthy dose of RPG, great. If you prefer your strategy a little "straighter", save your cash.
The demo is a well-rounded 333MB, and if you like what you see, you can take advantage of a Steam sale running at the moment whereby Dawn of War II is selling for 25% off.