I think the NWA will be the launching customer. NWA already has options for any Bombardier aircraft and with the oil price skyrocketing, both DC9s and even CRJ900s are no longer economically attractive.

C series will be flown by Mainline NWA pilots due to the scope clause. NWA already has experiences with the Embraer 175s and the feedback is not that great. It's even less economical to run than CRJ900s and has electronic maintenance issues. A maintenance tech told me they have a nick name for E175s, they call them E180s for making a 180 turn to return to the gate soon after pushback. So, NWA is likely to go with the C series as a DC9 replacement.