I think we'll see something like:
Staying
Aljaz- A very popular addition this year, he's managed to make Abbey (who a lot of people were disliking before she'd even set foot on the dancefloor) a hit with the viewers, and is now the show's "hunk in residence".
Pasha- He thoroughly enjoys the show and carries one of the largest fanbases. Doesn't seem likely to quit, and producers would be barmy to sack him.
Kevin- A revelation! Despite seeming to be a last minute addition to the roster, he has, for me, had the most impact for a debuting pro since Artem.
Artem- Speaking of which.... I think he'll be there for the forseeable. The closest we have to Derek Hough in terms of innovative choreography.
Iveta- Very popular with fans and taken an average dancer to the upper echelons of the competition.
Anya- Another last minute replacement (I'm sad we didn't get Emma but thrilled to have Anya), she's worked wonders with Patrick, and deserves to stay on merit.
Natalie L- Will she be back? I don't think the producers will have the gall to fire her, so her return is all based on her recovery. I'd like to think she'll be a certain name for next year.
Likely
Anton- He might be knocking 70, but Anton seems to the the pro that will not go. Likely to come back, but a presenting role might mean his skills are transferred elsewhere on the show.
Karen- This time last year, a lot of us were thinking she might not be given a second go. Whilst I'm glad she did, the tabloid "feud" with Ola might not have stood her in good stead with producers (that's assuming, and it's unlikely, that there's any truth at all in that nonsense)
Robin- Never been the strongest choreographer and that was evidenced (to Deborah's detriment) more strongly than ever this year. Appears to be quite popular, though, and is used a lot for touring/ specials.
Brendan- He's been there from the start and has history as the first winner, so I think it's likely he'll want to be there for the shows 10th birthday. Might call it a day for 2015, mind.
Kristina- Despite spending much of this past fortnight looking like she wanted to poke Len in the eye with a very sharp stick, I don't see her leaving. If producers decide to bin Robin, she's in more danger, although I think she brings more to the show as a whole than her dancing partner.
Leaving
James & Ola- The pitter patter of tiny tap shoes can't be too far away, so I imagine they might take a (temporary) hike to concentrate on that. James won't want to call it quits completely until he's won the Glitterball, though.
Janette- Made even less of an impact than Jared or Hayley (but had a far less likeable partner than either of those.) I don't think she was a particularly strong choreographer, but her relationship with Aljaz might win her another year.
Aliona- They already sacked her once, and then, when forced to re-hire her, gave her a 69 year old Golfer who's been out of the public eye for several decades. She's a goner.