Looks like there'll be some good stuff from iD Software at E3 this year. They gave this tease regarding Doom 4 though:
Doom 4 is "not a sequel to Doom 3, but it's not a reboot either," the CEO teased further, entirely ignoring the bit where GameSpot asked if it was a prequel. "It's a little bit different than those, and if I told you why, I would get my ass kicked."