We just got a new Wii 3 days ago. On the 2nd day, my husband and son were complaining of having sore arms. They finally realized it was from the aggressive "Boxing" the day before on the Wii.
Just yesterday, my daughter smacked her head with the remote when she was throwing the "Bowling" ball a little too high. Thank goodness, the remote was OK. (yes, her head was too).
I got the Wii online with our wireless router and downloaded the system update. I think I'm gonna get some of those new Rayovac "Hybrid" rechareables too. Now the next thing is deciding what games to buy.