If you have an XBOX and a PS3 then I can see why it would be nothing to be excited about. Except for the fact that the motion controls make it a much more immersive experience. I have used wiispeak in a private game and it worked well once I got a little closer to the TV. I haven't tried any of the other online FPS games though.
If you've got low expectations then it won't disappoint. But I still think once you try the multiplayer for a few games you'll enjoy it.