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 wouldn't count on it. No one was willing to lend any money to Pinnacl ecept Delta. Delta is now calling the shots for providing DIP $. Delta does not want Pinnacle to have other customers like United or US Air.