A lot of the Q400's are pretty old. I think Alaska/Horizon and maybe Colgon/Continental Express have mostly modern fleets, otherwise Bombadiers are an aging bird for most carriers.
Best flight to/from a regional airport I ever had was on an Embraer ERJ 145, a 50-seater jet, though I think they make 37- and 44-seat versions as well. Much quieter than most turbo props. I think Embraer makes 70-80 seat jets now as well as a 90-seat jet that's starting to be used by major carriers. There doesn't seem to be the demand for smaller planes right now; the airlines seem to want to fly fewer planes with more passengers.
However, since turboprops use significantly less fuel, even as they get larger (70-90 seats), we'll probably see more of them, as fuel prices over time will probably stay high.
The only viable turboprop there is right now is the Q400 and it's a maintenance headache, so new carriers are steering clear of them. The upkeep of them takes away any value in fuel savings you might get, plus the cost of a new one is already up there with the jets. The E170 and E190 are really nice RJ's. Better than the CRJ 700 and 900. I'm 6'5" and I can stand up in the ERJ which is nice, feels like a real airliner. All the 50 seaters, Embraer and Bombardier, burn to much fuel to be cost effective anymore. When gas was cheaper they were good, now they suck. Delta has already begun thinning out their 50 seater fleet in favor of 66 and 76 seaters.
