Andy, I picked this up a few weeks ago but haven't mastered aiming/firing with the wii remote, and my movement skills are clunky--not nearly good enough to even THINK about going on-line. I'm definitely a mouse/WASD kinda gamer, going way back to COD2 and clan tournaments
I did spring for the wii rifle, which helps, but I had to unhook the nunchuk to make it usable.
So I don't have any pointers, but I will say that I practiced zombie killing and 1v1 with my old college roommate. We both suck, and I died a lot, but it was fun!