New game from ID Software. What will it be ?

It is reliably known that at the present time ID Software is working on a "top-secret project", about which at the moment absolutely nothing is known, except that it will not be a continuation of the Wolfenstein, DOOM or Quake series. ("Enemy Territory: Quake Wars" does Splash Damage, and the new "Castle Wolfenstein" does Raven Software.)

My guess is Carmack's next game will be an MMORPG (Massively Multiplayer Online Role Playing Game) in some completely new, original universe.
Why I think so:
1) If successful, it brings the most money to developers. (World of Warcraft)
2) Technically quite difficult - Carmack is interested :)
3) Lead Programmer of World of Warcraft, John Cash, previously worked with Carmack on Quakte - they probably still keep in touch and exchange technical ideas :)

State your suggestions 8)