There's nothing more I'd want on the Wii than a Donkey Kong adventure that mixes the 3D gameplay of DK64 and 2D gameplay of DKC, then updates them both with gorgeous graphics, and Wii pointer stuff. Something that has that same wonderful jungle ambience that the original Donkey Kong Country had (the other two, excellent sequels sort of went for a different feel).
I really enjoyed Jungle Climber - I thought it was a fantastic game. The King of Swing games have always felt like nice tributes to DKC.
As for a possible Wii game, I think that given the two taget audiences the game will probably have (gamers and non-gamers), I think they might end up doing something along the lines of a virtual safari type thingo. Or at least do their best to give it that feel. Remember the pop-up books you read as a kid, and there were flaps you lifted up to reveal hidden characters and stuff? They could do something similar with the pointer. Have it so you see a leaf rustling in the jungle background, and you could hover over it with the pointer, and press a button to reveal a hiding monkey or parrot or something. Cool stuff like that for the non-gamer.
And for the platforming fanatics like us, a nice mix of sidescrolling and 3D exploration. You could have whole levels that play out from a side-on perspective, but might also have 1 or 2 little 3D platforming rooms that you can explore and move around freely in spread out in there somewhere. I say 'rooms,' but most of those little 3D rooms would probably be outdoors in the jungle scenery anyway. These rooms might yield an animal buddy after a short puzzle, which you could then take into the rest of the sidescrolling level by taking the path out of the 3D room. Those rooms could even offer up alternate paths that take you along an alternate sidescrolling part of the level.
Whatever comes, I'm sure it'll be great.