Ocelots--Salvador Dali owned one. I feel there's a large potential for these smaller cats to end up a common exotic pet given they're cute and catlike but still very distinct. They have the same utility as cats in terms of pest control, but even better--they can munch down a bag full of mice and can easily take out a rabbit, squirrel, chipmunk, etc. Of special note is the Asian leopard cat since it actually was domesticated at one point several thousand years ago.
If it counts, then Australian feral cats which appear to regularly grow longer than 1 meter and have evolved a distinct gait and musculature. Some call them "panthers", although they don't seem to grow larger than a lynx. If left to their own devices, they'll probably evolve into a cat version of the dingo within a few thousand years. They could easily be a small, niche export of Australia as a new breed of cat which may be the largest breed of cat in the world.