General thoughts about the news and other comments from this thread:
In my opinion KSD's scripts and especially plots never really met the enthusiastically embraced potential obvious in the character's rebranding, McKelvie's [most..] iconic costume [..of the 2000's so far?] and the equally iconic early promo and cover art by McGuinness, McKelvie and later great interiors from Lopez. It didn't help that the early interiors from Soy and Andrade and even the excellent Emma Rios were so markedly different from the bold pop style that had caught everyone's imagination, but the writing never really did it for me either.
Maybe that's a problem with specificity to an extent.. the concept said "Wonder Woman caliber A-lister for a forward looking Marvel era" but that's such a simple abstract concept that no one chapter in a heavily serialized story could ever hope to encapsulate it. But what IS big and amorphous enough to encapsulate it is Fandom, and DeConnick did an amazing job for her part in cultivating the Carol Corps.
So, her legacy with this character is secure, and she's got a TV enterprise to run anyway, and at least two awesome continuing series in Bitch Planet and Pretty Deadly.
How does the movie affect what Marvel does with the character next? Probably not in as many ways as you might think, yet. We're still about 3 years (!) from the time frame generally reserved for a movie-centric push, so the most they really NEED to do until then is not squander the goodwill they've got. Going supernova A-list now isn't outside the realm of possibility, but could be a difficult thing to hope to maintain all the way up until the movie's release. I'm not sure what super A-list would look like.. Gail Simone? Warren Ellis? And yes, I do agree that Dan Slott is an A-list writer who could write a great Captain Marvel book, but here's the thing.
I'm 90% sure the more important criterion in choosing the next writer is maintaining the positive conceptual direction and goodwill of the fanbase, as opposed to wowing everyone with a big name. Any male writer isn't going to look great on paper following KSD, and there's nothing wrong with that, it's just how it is; having a woman behind the book and as defacto fandom figurehead has been a major part of Captain Marvel and it would be crazy to derail that (though it is kind of funny to imagine how much more scrutiny Dan Slott would get if he was the guy who killed Spider-Man/replaced him with Doc Ock, AND replaced the head of the Carol Corps with himself. Ha ha...)
So, taking all the into consideration, Kelly Thompson seems like a pretty good bet. There's no reason it can't be an up and comer like her rather than a big name as long as they can carry the baton and do good work - and how are we going to get more big names if the ones we already have get all the big assignments? If they did go for a big name I'd still expect it to be a female one, and after Gail Simone there aren't a lot of huge ones to choose from, though G. Willow Wilson is getting there and is already Marvel exclusive, with Marguerite Bennet and Noelle Stevenson having also recently done great work for Marvel.. (I have been wondering if Simone would take a big gig with All New Marvel, but I'd been kind of hoping for her on X-Men.)