COD WaW is a solid game, and now can't wait for the next installment. Beat it on normal in about 6 hours, which is short. Right now, going back through on Veteran and trying to get all the achievements. Veteran is pretty tough, similar to COD4. The never ending barrages of grenades is fun.
Multiplayer is just fine, IMO. Some of the maps are HUGE, like Airfield and Seelow Heights, which I like. The spawning could use some improvements. I don't know how many times on maps like Asylum I'll spawn and immediately be killed.