Well this is actually semi-old news, but it's true! Id Software is officially working on Doom 4 and Quake 5 possibly on the way in the near future!
They have not specified platforms yet other than it will be on PC for sure but you can expect to see a XBox 360 and PS3 version probably such as they did with Doom 3. though undoubtedly a much stripped down version. The XBox version of Doom 3 had 1/4 the length of a single player and the graphics were on a setting lower than the low setting for PC.
I'm sure we can expect to see amazing graphics from this though surpassing Crysis and many other games and I can't wait to see more information on it! This will definitely be a must buy for me, I loved Doom 3 and the other Doom and Quake games.