Nintendo offers free support & repairs. If you have a hardware issue, like most of the ones I've just read, call Nintendo. They'll be happy to replace it if you haven't voided the warranty. And judging by what you guys have said, none of you should have.
I should notify you that Nintendo gives you 1YR free warranty. The Wii hasn't been out for 1YR yet, though. xD
Call your local Nintendo help-line and you might get a free replacement or repair. And don't worry about data loss, they switch over the memory or something - or just repair your console - so you won't lose memory UNLESS they said you will.
Good luck, guys. I hope your wii-motes are fixed.