Basically, it removes a lot of the base-building research stuff that was in DoW1. You essentially have your primary base, with 3 tiers, and you can build 2-5ish different units per tier. Two types of resources, which are obtained by capturing points on the map. It removes some of the emphasis on base-building and places it more on capturing territory. There's a lot of back and forth. You capture stuff, expand, the enemy gets behind your lines, you chase him again, cat and mouse, etc etc. There's destructible terrain and cover like in CoH, but it seems a lot less useless.
The AI is braindead. I haven't seriously played a RTS in probably 3-5 yrs. Nick + me + expert AI destroyed 3 expert AI in our first go. Then did the same with a hard allied AI. And then again with easy. The game's already gold, so longevity of skirmish looks questionable at best.
Anyhow, I enjoyed it for what it was, but it wasn't a massive change from other RTS. Not being a RTS fan in the first place, I don't think I'll bite for this one. Co-op campaign is nice and all, but the core mechanics are just kind of ho-hum.