just start over man. its not like any of those games require lots of time to build up
If you had a complete file for MKWii or Brawl it'd take tons of hours to get that back. Reunlocking everything, re-beating Subspace, getting all the trophies/songs/stickers? That's extremely time consuming. And MKWii, doing well in all the races to get everything and so on.
And Animal Crossing means an entire town, all the items you had, the villagers, the debt paid, the catalog/museum completion, etc are all gone.
Those games require probably hundreds of hours to regain what gets lost from them if you don't transfer them.
Personally, once I get my Wii U, I am saying screw it to having most of the stuff on the Wii Menu and will just redownload them all from the shop. My save files have priority to the minor inconvenience of redownloading my less-than-20 VC/WW games.