First of all, Kirby > Donkey Kong. Maybe not in sales, but in awesomeness!
Secondly, I think most people will agree that sales will likely end up GT > Zelda > DKC.
If I had to give numbers, I think they'd probably do something like this:
GT - 8-12 million
Zelda - 6-8 million
DKC - 3-5 million
But that's assuming DKC lives up to it's SNES predecessors. Given Nintendo's attitude towards marketing their smaller titles these days, it could be sent to die like Punch-out and others if they don't deem it worthy of their blockbuster marketing. It seems to be all or nothing with Nintendo, which is kinda sad.







