I'm hoping they do like they did in D/P where theres a bunch of evolutions for previously neglected pkmn in the expanded dex.
Banette, Weezing, and Jynx evolutions would be sweet. If they buffed some of the truly NU like Arbok, I'd be REALLY happy.
Well Arbok's poison-type. The type just isn't that good - in fact, I think it's a strong contender for worst type. If you look at the current poison-types in OU; Gengar's Ghost/Poison, and would arguably be better off pure Ghost. Roserade's OU due to its movepool, and most of that seems to come more from the grass side; again, I'm not sure the poison typing helps. So for Arbok and Weezing evos to get a decent presence in standard (even if not actually OU), I reckon they'll need either a good second type, a killer movepool, or absolutely excellent stats.