I suspect it's harder to get production rights for unproduced toys, but I may be wrong.
I don't want any non-pony characters, honestly. The only exception would be princess dragons, although I already have the originals, it's just that they're special...
The one prototype I'd want is baby shady. Otherwise while they're awesome to look at, I'm not desperate for them to be produced. A regular eye Baby Shady would make me happy, though I do have a beautiful pandabearchan custom of her in that pose already.