additive dynamic lighting! non of that raytraced shadowmapped shader crap!
Yes please!
No, really. The use of multiplicative lighting is why dynamic (weapon, etc.) lights don't illuminate pitch black areas.
Additive lighting, proper model lighting (no more magic fluorescent structures), offloading more rendering work to the GPU and possibly HDR would be a great improvement without the hassle of trying to kludge tons of modern graphics features into Q3, and updating all of the content to use them.
