The Official Nintendo Magazine (ONM UK) has a few more details about DK Jet for the Wii:

– 7 worlds with unique dangers (Jungle level has windmills, ocean level has octopus)

– Weapons in the game, only one confirmed is wooden bazooka

– Collect bananas for speed boost. Boost is supposed to be ridiculous speeds like F-Zero

– 4 player local multiplayer confirmed

I’d like to see more about this game before I make the decision to buy.  Hopefully we’ll hear more at E3.