Well, I bought it yesterday. Didn't play it much but it's OK so far. It's not as polished as CoD4 (Treyarch made WaW so it's no surprise). The NPC's movements are too erratic while the CoD4 NPC's had more fluid movement. Also the player models are also a little weak too. The reload animations look kinda like mod animations (high quality mod animations but still lower quality animations than CoD4). It feels too much like an expansion of CoD2 really. The story isn't as well told as CoD, CoD:UO, or CoD2, (none compare to the stellar story of CoD4 though).
But still despite these drawbacks, it's OK. I personally wouldn't waste the money on the special edition like I did unless you want the extra **** like having the FG42 unlocked in multiplayer (I don't even like it) and a week of double experience. Oh it also comes with a special tin and a fake canteen.
By the way this is the PC version.