You guys are pretty much right on the money. Competition, habitat degradation, climate change, and hybridization are the major hurdles native trout are facing in the west. Read TU's "state of the trout".. [log in for link]
We have a long, long way to go.
Stocking greenbacks/colorado river cutts willy-nilly isn't the answer. 1) They're prohibitively expensive to produce, and 2) they'll hybridize with any other cutthroat/rainbows already in the system. So if you stocked a bunch of greenbacks into Georgetown, for example, it would be a massive lost investment. They would just cross with the rainbows already there or get eaten by the browns.
Add to that the fact that many systems are riddled with WD (which limits cutthroat breeding) and you're limited to a pretty small area where you can stock and maintain cutthroat populations.
My ultimate native trout dream is if they killed out everything from georgetown dam upstream and loaded it with native cutthroat. Georgetown is actually pretty fertile and would grow good-sized fish. The river above the reservoir is great spawning and rearing habitat. I don't know what WD density is in that area, but screw it, I'm dreaming.