The game came about from an experiment with something on the Wii and, in keeping with that experimental model, Rage for iPhone won't have a four-year dev cycle: It will be out this year, before Rage, and it will be cheap, in keeping with the iPhone App Store's model. A second Rage iPhone game will be released alongside the release of the PC/console release next year, and Carmack is still "spot-surveying" the Android market to determine if it's worth supporting. He said it won't happen "this cycle" but he'll reevaluate in about six months. More news from QuakeCon as we hear it.
[Update: Now with video, found after the break! Update 2: John Carmack clarified on Twitter: "The iPhone demo was not "idtech5" on ios, it was from scratch new code. A tool in rage exported custom data for it."]