John Carmack may have released quite a big cat from quite a big bag at QuakeCon. He made comments in regards to a version of Quake Arena making its way to the DS during his keynote. He also said that, should it happen, he'd want a different control scheme than you may initially expect.
Unlike the touch-screen input of Metroid Prime Hunters, Carmack voiced his opinion that a d-pad, restricted movement control scheme like that of Doom would be better-suited to the title. Personally, if this were even to happen, we'd prefer the touch-screen controls, as they more closely resemble the mouse and keyboard. Of course, Carmack's intent to put the game on the DS isn't anything new, but it's certainly a bit more plausible now, if we may say so.