I was actually marveling (no pun intended) last week that Sabertooth's first appearance was actually in Iron Fist, near the end of that character's first volume run.

I do wonder how they'd be able to pull off Thunderbolts in MCU; currently, all the 'villains' seem to be dispatched and never seen again, though I suppose Abomination is still kicking about somewhere. Personally, I'd love to see Alpha Flight make an appearance. That'll be possible with the X-Franchise now in Marvel's hands, though I suspect they've not even be thought of yet.