Great post & thread. Agree that 2112 has to at least rival TSOR in terms of vocal strain.
My view is that Rush has always given 100%, and as a fan I'm happy with any new experience I can get with this band. I loved the setlist in Pittsburgh, but I'd probably say that no matter what they played ....
I think this band has at least one more album in them. As for touring ... I think we're looking at a three to five year window max for it to happen. Perhaps one more tour, but with fewer dates (and more days off in-between, if they can swing it financially & logistically). If they do a second leg of this tour in North America in 2013 with a revamped setlist that favors more classics, that could be telling.
Let us consider ourselves lucky no matter what.