If I can get it all done; myself and a couple friends are doing the following:
1920's Opal, Spike, and Gummy
Pinkie Pool, and possibly Derpy-ender and AJ as Weasel
Smarty Pants, Sleepytime Luna
Also in the possible mix are: Hippyshy, Nightmare Rarity, genderbend Rarity, and Snowfall Frost
If I don't die of exhaustion first it's going to be a great con!