Skywest is a likely suitor, but it does take a long time to get a training program AND proving runs completed.
They are a likely contestant. They face the challenges that you stated but also have the man power to get 30 new airframes up and running. They'll have to do hiring but not as much as a company like C5.
CommutAir doesn't have a chance. Their owner is extremely greedy and they are SUCH a small operation with only 200 or so pilots. You are talking about a 160% increase in operations in 6 months. CommutAir is out.
I think they have a slight chance, as they are already a DHC-8 operator and for United none the less. The battles they face are staffing the planes (pilots+FA's), upgrading MX and general support (DX, scheduling, etc.) for the airplane. One thing that is not helping them is their on time percentage. I have no idea what it is, but it can't be good with their MX gripes and the 300's were a disaster getting them online but maybe they'll tell United that they learned from the experience and can do better??
I think it would about be what Colgan went through getting these airplanes up and running. Remember Colgan was a small group too when they first started getting the Q's. I don't think C5 or anyone for that matter can get 30 Q's up and running in less than 6 months.
Mesa has a Dash 8 training program with pretty low 70-seat wages. They could seriously take over this flying with a long-term deal and leases on the airplanes.
See below. Does JO even have the money?
Republic is a small possibility.
I think they've got a better shot than Mesa personally.
Pinnacle. There is a good chance that these airplanes don't go anywhere. The BK declaration said that United and Pinnacle were in agreement on a long-term Q400 deal, however, Pinnacle could not submit a competetive bid for the business. If Pinnacle does (and they will) shed a bunch of labor costs via bankruptcy I think you could see a bankrupt PNCL submit a bid to keep these aircraft.
I don't think there's a chance in hell that PCL keeps these planes. Delta has them by the balls with the DIP financing or whatever and part of the deal was to drop the Q400's leaving United scrambling to replace the lift. Pretty smart move on Delta's part, but sad that they play that way.