I think we're overdue a pony, if you think about the varied breed types we've had so far. A draft horse, Hanoverian for a warmblood, Lusitano ticks off an Iberian breed, Friesian for a carriage breed, Arabians and another light breed in the Marwari, then the Criollo represents stock horses even though it's less common and well-known than the QH and Paint most brands make. This leaves no gaited horse, and no pony, as the major breed types not represented at all. A TWH or Saddlebred could be sculpted in good flashy dynamic poses, but would be yet another horse-sized addition to the range, I'd rather see them go for a pony breed cos that's a bit more different to everything else they have so far.
And I might be biased, but I'd love it to be a proper Shetland. Not the long-legged fine-faced Shetlands a lot of companies give us (influenced by American types and miniatures), but a true island-bred type like a scaled-down draft horse, with solid short legs, a large head, a wide bum, and a lot of winter-proof fluff!