The votes for this came up in favour of people turning into My Little Ponies, so that's what's going to happen! Next Saturday (May 17), anyone who wants to will wake up as a My Little Pony.
The only proviso is that people don't turn into an existing My Little Pony (though you can use them for PBs) character, but rather themselves as a My Little Pony.
To help with icons, there's this site here:
Make a My Little Pony (Though it doesn't seem to work in Firefox) and some blank pictures I uploaded
over here!
ETA:
This looks useful, too!