Mew, Celebi, Jirachi and Manaphy should (and hopefully will) get one soon.
Other than that, the Original Eeveelutions (although with the new Leafeon and the newer versions, that might be a bit too overpowering, we'll see), Venomoth, Seaking, Cloyster, Hypno and Wigglytuff (for being some of the most awesome Pokémon ever), and stuff like Quagsire, Drifblim, Dunsparce, Gastrodon and other stuff which doesn't get nearly enough love.
But I'm guessing we'll 1st see Groudon and the gang, the Hoenn starters, Dialga and Palkia again and some other lame stuff before we'll ever get to those, which we probably won't...
The Kanto and Jotho starters will probably get a set of their own if a Jotho remake comes out, and they deserve it.