What I would like to see...first the evolutionary steps: i'd like to see a rotating tailcap to activate the light instead of the bezel. That could also allow a way to isolate the battery compartment so that the battery wasn't involved in directly compressing the QTC. I'd also like to see an orange peel reflector for improved beam qualities. A well designed pocket clip and attachment method is a must, imo.
I don't care anything about copper or Ti, aluminum works fine and is probably cheaper but if we're dreaming, i'd like a larger sized tactical/pocket (e-series sized) light with QTC and a rotating push-tail switch like the mountain series only capable of being turned to lock the output in position. ie...push the tail switch to activate then turn it for constant-on at that brightness level. That would be a revolutionary tactical light, again imo.