Important note: Kawasaki owns the trademark to the term Jet Ski and a personal watercraft/wave bike can only truly be called a "jet ski" unless it's been made/licensed by Kawasaki. (Even though the term has pretty much fallen into fair use).
Well, well, WR64 got released on the Wii U VC in Europe yesterday and after seeing chatter via Miiverse about it and some confirmation via YouTube videos, looks like Nintendo actually did a little change to the game . . .
To keep this short
N64: Wave Race 64 has the Kawasaki license and includes banner with the Kawasaki name/Jet Ski around the game and on the title screen (with trademark details at bottom of screen)
Wii VC: The license expired and the banner were replaced with Wii and Nintendo DS banners (This is the cameo and is already mentioned on the site).
Wii U VC: They got the Kawasaki license back as the banners appear to be original N64 ones, details appear to be the same as N64 ones as mentioned above.
This seemed pretty surprising personally, didn't think Nintendo would actually bother to get the license back. Possibly it could be following reasons:
1) Knowing that the Wii/DS banners would look even more out of place in this year. 2) Can't be bother updated those banners to include a Wii U/3DS logo but just cheaper to get the license back and possibly to use it for a future WR game as well?