Marvel gets to use Quicksilver and Scarlet Witch but can really only call them gifted as any mutant reference is not allowed. No references to any mutant heritage of any sort, on the flipside Fox can't talk about either of the two's Avenger teammates/shenanigans. It'll be interesting to see how this plays out, but the casting on the Avenger's side looks to have been better, in theory anyway. We wont know for sure until both movies are out.
If I remember everything correctly Fox has all Mutants and Fantastic Four, Sony has Spider-man and all his group, and Namor is at Universal Pictures. Even though Fox has the Fantastic Four I don't believe they got the entire history of characters as Marvel has Black Panther and Inhuman stuff in planning I believe so the Fantastic Four deal must've been sliced up a bit before hand on what they were allowed to use. I'm really surprised that deal didn't somehow include the Inhumans.