While I would agree that Doom3 was a casualty of the effect you outline, most of the stuff Carmack is working on now is very much within the realm of current & future hardware.
The megatexture tech is a clever use of 'clipmaps' or virtual mipmaps and runs on current-gen hardware. They are currently looking at a sparse voxel octree technique to create a megatexture-like (theoretically)infinite LOD system for geometry. This is also intended to be used on current (or near future) hardware.
A lot of the graphics techniques used by id aren't invented by Carmack, his genius is making them run in realtime on consumer computers. And yes it can be a guessing game :)
The megatexture tech is a clever use of 'clipmaps' or virtual mipmaps and runs on current-gen hardware. They are currently looking at a sparse voxel octree technique to create a megatexture-like (theoretically)infinite LOD system for geometry. This is also intended to be used on current (or near future) hardware.
A lot of the graphics techniques used by id aren't invented by Carmack, his genius is making them run in realtime on consumer computers. And yes it can be a guessing game :)