MY WII WAS FROZEN TODAY! (oh come on, someone had to say it)
Too bad about the Wii though. I wish these systems had a better way of dealing with corrupt memory, or had a way to restore a Wii to factory condition (just provide a "Restore Mii!" disc with every Wii), or downloaded system updates in the background (you know, like a normal computer does) and then had a SAFE way of applying the update so it would continue where it left off if the power got disconnected along the way. Sounds like you tried reformatting the system memory and got a dead console, which I would not expect from a feature that sounds like a "restore to factory condition" option. Given the XBox 360's highly-publicized maybe-or-maybe-not high failure rate, just give us the option to back up all of our saves (including F-Zero GX and online-enabled Wii games) when we want and how we want. Screw the possible application of cheating or privacy concerns: we'll always find a way to cheat, and design the system better next time if you can't separate online data from offline.
I mention once again the high-capacity low-reliability third-party memory card I had for my PS2. Okami was the game to corrupt my memory card. I had difficulty saving the game, investigating the memory card led to all Okami saves being marked as "corrupt data", for some idiotic reason many corrupt data blocks cannot be deleted, and thus trying to save data for ANY other game became impossible with that corrupt data existing. I'm past the point of caring whether I can recover anything on it (even if that means losing all 60 hours of Final Fantasy X and all 70 of Okami), I just want the corrupt data gone so the card will start working again. You might say "just reformat the card". I heard you have to get some other utility to do that, that PS2 doesn't have a built-in feature to reformat a card like GameCube does. Or you'd say "just buy a new card". But I'm too lazy to do that.
In short: Sorry that it had to end the way it did, it happens to a lot of us (I almost screamed when Mario Golf glitched and deleted ALL my data), get a new console and hope it will be many more years before it happens again. You can try backing stuff up if you wish, but remember that memory cards sometimes die out too. And computer hard drives. And servers and cloud services go down occasionally too. Overall the chances of a system or memory card going kaput is very low (and I bet corrupt files on system memory is a rare issue), so in most cases you don't have to worry about it too much. It happens, you grieve, you move on.