I would hope they'd stick with Retro developing, I'd love to see what those guys do with a 3D platformer. I'd hope the collectibles were toned down from DK64, the worlds weren't so big and empty, and that it had more focused gameplay instead of doing a billion things.
Just getting rid of the music pad stuff, guns, and the weird special attack stuff would go a long way. It would be interesting to see them try and incorporate the animal friend stuff in 3D, maybe something like the animal stuff in that Sabreman Stampede game Rare was making for the Xbox at some point.
I doubt it's gonna happen, especially any time soon and from Retro (I think they've probably moved on from DK at this point) but if there's enough of a collectathon resurgence never say never I suppose.