The future of id is on consoles, with all the other developers.
id's recent engines no doubt failed to pan out because they didn't develop for the 360. Let's not forget the biggest shooter in the world, Call of Duty, is still based on id tech. Maybe once Rage gets out (and if it's successful) we'll see some demand and usage of Tech 5 for the end of the 360's lifespan. Same with Crysis 2.
Steam + PSN: PHJF