I tried the multiplayer beta way back when and enjoyed it. I've wanted to try to get better at RTS games, and this one takes out of a lot of the drudge and micromanagement of more traditional games. Too bad I won't be able to play it until I build my new computer.

I enjoyed the single player, but couldn't really stand multiplayer. Not expanding your base or being able to build defensive structures just doesn't appeal to me.

I enjoyed the first dawn of war (and it's expansions) WAY more.

I'm with IRG as far as single player goes (definitely not the preference of DoW 1 though).
The single player is great, and I love how they switched the focus of gameplay from micromanagement to combat tactics, it makes for a much more rewarding game.
I've finished DoW2 more times then I can count, admittedly with new mods on each time. The expansion is rather short, but I do enjoy the addition of chaos and the new abilities. Personally I'm waiting on more mods before I'll boot it up again.