DK Bongo Blast was announced at E3 last year (no release date was given) But they are saying that it will be out by the end of this year (but I've heard rumors it may be out by summer but those are only rumors)
The game looks pretty fun and hopefully we hold us over until Mario Kart comes out in 08 or 09.

http://www.youtube.com/watch?v=bxkbLQNpxxE
^go here to see trailer