Here's how our current contracts defines a Commuter Aircraft. I don't think this is as big of a deal as some are making it out to be. Notice the last sentence...
The term "Commuter Aircraft" means aircraft (jet or turboprop) that (a) have a maximum of seventy-six (76) seats (as operated for the Company) and (b) are not certificated in the United States with a maximum gross takeoff weight (MTOW) of more than 86,000 pounds. If an aircraft otherwise meeting the conditions in the preceding sentence is being operated for the Company and is recertified in the United States with a MTOW of greater than 86,000, said aircraft shall remain a Commuter Aircraft so long as it continues to operate for the Company at a MTOW of no more than 86,000 pounds. The existing seventy-six (76) CRJ 900 and E175 aircraft operated on behalf of US Airways, Inc. as of January 7, 2013, are grandfathered as to the seat limitation, and they and their replacements may be operated with seventy-nine (79) and eighty (80) seats, respectively.