Jones mugs a bit -- though nowhere near as much as Fallon used to -- but I think she's filled her roles quite well. I've even seen some people suggest she take over Jost's position at the Update desk, though I don't think that's likely.
As rough around the edges as Jost was starting with Strong and even into this first season with Che, he's started to grow into it, and his chemistry with his co-anchor is building rather nicely. Neither of them are up to the level that Strong was, and I still find it unfortunate that she didn't want that chair anymore, because she was absolutely superb, but Jost and Che are coming along. I'd give them at least another season together to solidify their partnership, and if it's not working after that, then move on.
McKinnon might move on after next season. Her Hillary is wildly popular, and she can ride that through the election. After that, though, she's got what it takes to spin her SNL stardom into more TV and possibly movies.
I think Bennett and Mooney are poised to be the next breakout stars. Their low-key characters are phenomenal, and they've proven their versatility in other ways as well.
Pharaoh, in my mind, has kind of stalled out. He's got superb impressions, and they're all popular, but what else does he bring to the table? From what I hear, he's not writing much. He doesn't particularly do one-off characters well -- or, at least, they never seem to find any great place for him in those roles, and given the way the show works, part of that is almost certainly a lack of self-promotion. Beyond having him fill out the remainder of Obama's term, I'm not sure where else they can use him at this point.
Davidson is going to have to step it up next season if he wants to stick around. He's got his "resident young person" title on Update, and he's done some funny things here and there in sketches, but he's otherwise just kinda there. He may well be capable of bigger and better things, but this is a show that demands those things on a consistent basis, otherwise you get lost in the mix, and he's in danger of that.
I think Zamata might be on the list of people to let go, as well. She hasn't really developed into the all-around cast member they hoped she'd be. Ironically, that role has been filled by Jones, who was brought on as a result of the same infamous search for black female cast members, but she was initially only a writer because they didn't see her as a good fit in the cast. Obviously that's changed. Zamata has filled bit parts here and there, and not much else. She has her one YouTube teen dance instructor character, but you can only do that one so many times before it gets old. Not that SNL has ever refrained from beating a dead horse, but if the dead horse is the only recurring character for a given cast member, it's not going to last very long, and neither is the cast member.