Really, really good. Me and Penguinman were playing it earlier tonight together. Very fast paced, lots of action, easy to jump into if you're new, or want to play a quick game (the typical game lasts around 10 minutes, because there is no base building or economy). It's heavy on micromanagement, which I usually hate, but it's perfectly manageable, because, typically, you'll control a half-dozen units AT MOST in multiplayer. Scale isn't sacrificed, though - the game supports up to 16 players on a server, so there's always plenty of targets for your artillery and air strikes, which are plentiful (and varied - you can call in napalm, tank busters, carpet bombing, and even engage in chemical and nuclear warfare).
Basically, in my opinion, it's the perfect RTS - it makes the clickfest manageable and fun. The only issues with the game I've had are technical (my graphics card is the one listed in the minimum requirements on the box, so no surprise there), and also there's the occasional problem of having all your support guys playing with heavy artillery instead of throwing out some AA to stop your tanks from getting raped by helis. Oh, and heavy artillery is imbalanced - American heavy artillery is crap, NATO's is decent, Soviets' rocks. Other than that? Awesomeness all around.