As the airline industry has evolved over the last decade, we are seeing the trend of mainline airlines bringing their regional feed in-house once again. (Or as in-house as legally possible aka United)

American: Envoy, PSA, Peidmont
Delta: Endeavor
United: ExpressJet, CommutAir

Will we begin to see the slow death of the multi-carrier regional airline, such as Republic and SkyWest? Delta is rumored to be going to 3 regional carriers and United is now investing heavily in ExpressJet. Thoughts?