This thread appears to be more dealing with the question of "why Airbus" more than a scope debate.
Boeing is getting their clock cleaned. Airbus picked up 900+ orders which effectively sells them out through 2018-2019. Boeing's 142 not only sounds bad in comparison, it sounds worse when compared with the 130 ATR's sold!
The big lessors are telling Boeing they need a new airplane. Something like this:
The idea being very low EPR fans with variable nozzles.
It will be interesting to learn why airlines like Republic and American have ordered what are essentially competing designs (the A319 / C Series & 737 / A320 )
Delta on the other hand has not ordered anything and now is pretty much locked out. There are no production slots until 2018 anywhere except the C Series.