I think that a lot of the weight issues will be mitigated by a smaller frame (which is what I am looking for and I suspect that I will have a lot of fun trying to find one with a non-slopping TT.) Drive train components do not add much to the weight (other than BB and crank - those are fairly big in weight reduction) - the difference between a full 200GS and a full XTR group is less than 1/3 of a pound as far as derailleurs and shifters go. Popping on a decent saddle and post and a handlebar and stem could save at least a pound, maybe more.

I am kind of looking for the proverbial sweet spot: low weight frameset with enough strength to take a beating, but I am not sure that this might exist...