I thought Desplat did a good job with the last two Harry Potter movies and I like a lot of the original stuff he's been doing too; he's certainly the current go-to composer in Hollywood atm.
This might be my favorite part of the Star Wars speculation game so far. Who gets the scoring duties.
I'm pretty certain Williams won't be coming back. Whoever they hire will use his themes, of course, but I bet they either approach him and he passes, or they just decide not to approach him.
I don't know that Desplat is THE current go-to, but he's definitely up there. I'd still put Giacchino above him, especially when it comes to something like this - there's a reason EVERYONE has just sorta assumed he'd get the job regardless of how this whole thing shakes out. And if he does get it - he basically gets to be John Williams AND Jerry Goldsmith all at the same time, scoring Star Trek AND Star Wars simultaneously. That would be fun as hell to hear.
Here's a dark horse: Alan Silvestri. He did a John Williams impersonation ONCE in his career, and that ended up being the Back to the Future score. He's never really tried again (Captain America was pretty halfhearted) but I imagine he's up to the task.
I've said before in this thread, but I think the composer who's proven he can work really well with leitmotif, to support the storytelling musically, is Bear McCreary. Question is whether anyone would even think to ask the guy as he's sorta pigeonholed as the DRUMSDRUMSDRUMS guy, even though his scores are way more complicated than that.
If Williams does get some say, I wonder if he'd suggest his protege, Joel McNeely, who has already scored the Shadows of the Empire media blitz from 96.
His cues from that soundtrack ended up being a decent predictor of what the prequel soundtracks would sound like.
I don't think Ottman is on the list, and I don't think he'd want to be. He's probably looked at has having had his crack at Williams w/ Superman Returns, and it wasn't any great shakes.