I'd rather have a 2D Metroid. The Donkey Kongs didn't really stand out as anything extra special. They were good, but I liked Mario better (and almost everyone did), and 2D platformers today are now so much better than the DKs, that I don't really see why another one would be anything super.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS