The E170/175 doesnt make sense at AMR considering the fuel burn/performance compared to the existing CRJ700. E190s are desperately in need for the AMR system, but you wont see any regionals flying them. They are mainline aircraft.

I dont think Eagle will get any new a/c until after 2012 and a new contract is signed. At that point I wouldnt be surprised to see some new 70seat turboprops (Q400 or ATR-600), get rid of all 37-seat and 44-seat ERJs (this will probably happen sooner rather than later). Eagle will be half the size it is today flying 25(maybe 50 at most) CRJ700s, a bunch of 50-seat jets, and 70seat turboprops.