All of my saved data - gone.
Wow. That really shouldn't happen.
I seem to remember Nintendo warning me quite explicitly when I sent my Wii in for repairs that they could need to mess with saved data, so to be sure to back mine up. So I did, backing all the data onto my SD card. It turned that I didn't need to do that for what they ended up doing, but it was still the smart thing to do.
Sorry to hear about your data loss, bob, but I get the feeling they probably warned you to backup your data. If they didn't, I'm pretty sure we did. If you didn't backup your data, well...you were warned.