Ok..I'll bite, this is JMHO, but

Mainline will continue to recapture RJ flying, begin flying large RJ's at mainline, cherry-pick profitable routes as RJ operators shrink and leave numerous cities petitioning for EAS designations to at least see service from Great Lakes as an alternative to driving a couple hours to the closest legacy spoke city.

DL already has CRJ900 and E190 rates, age 65 retirements haven't even kicked in yet but are expected to reach 600/yr in the next 3 yrs. and the same thing is happening at the other legacy's. Even if they recinded the 1500 rule, there aren't enough pilot starts to cover the future movement of current RJ pilots to mainline. The course is set..RJ providers will start to shut down, smallest to largest, in the near future. Raising RJ pay won't stem the tide, cause mainline will be flying large RJ's at mainline rates..and only the senior RJ lifers will hang on for QOL.

ULCC's may try to fill the void as cities lose service. Allegiant is a great example of finding city pairs that can be profitable, but we're talking about the very smallest markets that lose RJ lift, and even Spirit will have trouble filling a 320 for $9/seat on a routine basis cause there just aren't enough O&D pax. If there are enough pax to go around, the legacy's will still service that city with mainline RJ's.

As the available pool of approx 11K mainline applicants shrinks, junior ULCC pilots will start to look at their options. We had JBU captains return to DL last year as their last chance to return from furlough after 9/11 expired. I don't pretend to know why, but there was movement from a LCC to DL, so I can only expect that to happen in the future as seat progression and new-hire QOL improves at the legacy's. We just had a 2014 new-hire get the right seat in the 330 in NYC, and others are getting SEA, LAX, SLC right out of training. There's a lot of opportunity out there, and RJ/LCC/ULCC pilots will have lots of options moving forward.

Of course, all of this is subject to change depending on the news ticker of your favorite network. And I'm just a guy who raises the gear for a living, but the future looks very bright for those pilots who take advantage of those options.

JMHO..