I think that the Waterfront area will stay built up. You can't get a seat at the freakin' Eat 'n Park (serving the finest in turnpike-stop cuisine) there on a Friday night! If it weren't for the traffic bottleneck (No city has more bottlenecks than Pittsburgh.) the Waterfront would be even bigger than it is now.
But if I had my druthers, I wouldn't mind living in that area. It's quite nice in some areas. Nice old architecture to the houses, or "haases".
When you say bottleneck, al I can think of is flying over the hill in Greentree on the Parkway and hitting the traffic at Ft. Pitt. It was there that I saw my Grandma swear for the first time. :o)