Considering US Airways has something like 7-8 regionals, I'd expect elimination and consolidation to occur on that side. Considering Eagle's present operation is a melted candle at both ends (excessive number of small RJ's on one side and an excessive number of $100-140,000/year pilots on the other), I'd expect contraction there. Divestiture may or may not occur along with consolidation (merger).
The degree of impact to each side is the wild card and it would appear even Parker hasn't dived too deeply yet into how he will modify that. It sounds as if the mainline decisions haven't been completed and that would occur before determining how the "Eagle" brand network and all its "feed providers" will factor in. Nothing but speculation at this point............