I'm not sure if this was posted before ot not, I saw it at one point on the first page, but it was ignored, and I don't have the time (currently) to check through the other pages.
Some feature in uploading levels/tilesets/etc that specifies other users that should get credit for it in their "levels by this author" area. Of course, the person specified would have to accept the crediting, because otherwise you could upload something which got lots of 1.0s and credit it to someone who you dislike, without them being able to do anything about it.. This would also cut down on all the "Flea and Rage" (more then one person) accounts.