After spending some more time with Company of Heroes, I feel confident in giving a fairer assessment.
I think it's a great extension to the RTS genre. The things that feel innovative in the genre tend to be small add-ons and refinements of certain ideas. It's not quite Advanced Squad Leader, but there are lots of ideas taken from grognard games. Cover is very, very important, so placement is a priority. The enemy loves to harass your control points with one or two platoons, which makes well-placed defenses key. Tanks have variable armor which means that flanking those Panther tanks is just about the only way to survive.
Most of the new elements work well, but there are still some sticky mechanics that seem to be problems in every RTS.
Top of my list is the vehicle pathfinding - it stinks. You don't notice so much in the earlier maps because you won't have many tanks and neither will your opponent, but on later maps the Axis will start pulling out lots of armor - you'll feel it then. Tanks won't line up properly when you right click and choose their facing. They won't turn around when their rear armor is getting hit - you have to click furiously and hope that they'll turn while traveling.
Then there's my most common complaint for all RTSes: When moving grouped units, the speed isn't capped at the slowest member of the group. Also, there seems to be no move order. Those kind of things should be automatic at this point. If I've grouped a tank, a platoon of infantry and an armored car, the tank should move slow with the infantry to its rear and sides and the armored car should be on a wide dispersion looking for panzerschrecks and snipers.
Defense is also a little weak. While there are lots of good defensive structures, it takes time, careful planning and a unit's attention. It would be nice to automate some of that process, or allow the engineers to queue up actions - you could plan your whole base defense in one go and just let them work.
A lot of the complaints can be mitigated in single-player by utilizing the Pause button. You can still issue orders while paused, so the whole game can play out as a semi-turn-based affair. This saved me during Mission 13, which was far too tough for Easy difficulty.
I'd love to see more cross-pollination of ideas between Company of Heroes and THQ's other big RTS property, Warhammer 40K, especially the detailed cover options and taking over unmanned battlefield weapons.
And it'd be great to have Dog Company go up against Chaos Marines.