Treyarch went with proven mechanics and took World War Two into a whole direction, successfully.
First thing is first, the tone of this game is much more mature than even COD4. Everything is bleak and the last few missions in the game really make you feel like you're immersed in the game. From what everyone is shouting during the game to the way the levels are absolutely murdered by gunfire and explosions, Treyarch did this one right.
The weapons in the game all feel like they have a good amount of balance, on and offline. Rifles are definitely the best weapon to choose from for most of the campaign and several of the multiplayer maps. Snipers are very accurate and very powerful, which is good because they are slightly difficult to use. I personally feel that the BAR is a little overpowered, but that's just my opinion.
Finding servers as of right now in the game is a little difficult if you haven't grabbed the patch 1.1, which wasn't announced unless you're following the game. The multiplayer is basically just COD4's with new skins and vehicles. Is that enough for some people? Of course. Is it enough for me? Yea.
The controls are fairly well done, but the grenade button is in a seemingly odd place for me, still. I never liked used the "G" button to throw grenades. One thing is absolutely definite about World At War, it's anti-hack program is amazing. PB does suck most of the time, but the way it works now is just awesome. I didn't like it but I did get kicked from a game for being 12-0 within 3 minutes. That just shows though that PB is definitely looking for the hacks and trying to prevent them this time around.
For anyone looking for a new WWII game or to upgrade from Day of Defeat: Source, this is the place to go. Great campaign (Online Co-Op too) and great multiplayer, good job Treyarch, you didn't screw this one up.