With Carmack stating that it will have three times the graphical richness of Rage (which in 'some' instances looks very nice imo), and if they adhere to the successful formula of the earlier games, it could come as no surprise that Doom 4 will require a decent rig to run it at to a high standard on the pc. I can't see a modern day level design with scores of enemies raining down on you without dishing out a lower frame rate, that is before the usual six month or so down the line where newer hardware is able to raise the bar again. If you can access the rooms in buildings and generally really allow the player to explore coupled with the old school game design of having numerous enemies on screen (and hopefully many levels), then it will naturally take a substantial chunk of system resources.
On a side note and although most certainly unofficial, I do quite like some of the art work out there :
I need to change underwear
Unfortunately this is what developers need to realise. Past games were excellent because of the gameplay, not because they looked nice (there are exceptions obviously that were both).
Everything that is churned out nowadays is all the same with the odd diamond in the rough, hence why we are all calling for remakes of Doom/FFVII/Silent Hill 1/Resident Evil 1 & 2 etc etc
I for one loved Doom 3 and remember playing the Alpha when I was at Uni at about 3am in pitch darkness waiting for one of those generals to leap out only to find a load of error codes appear in the top right and he magically appeared right in front of me - I nearly soiled myself.
