Regionals should thank mainline a lot that they even exist in the BIG fashion that they do; after all, the whole "No B-Scale" thing may have been stopped at mainline, but there is a de facto B-scale operation going on with regionals doing increasingly more mainline flying with personnel costs that range from "inexpensive" to "bottom-basement". Regionals are more appropriately called major airlines these days—this is one place where the earlier generation gave up the store.

AFAICT, there's no sign of trouble on the SkyWest side of operations...parking 50-seaters or not, SkyWest does (and will continue to do!) a LOT of the flying that used to be Delta/Western Mainline out here on the left coast. I'd consider SkyWest fairly loyal to Delta—it's not like they would disappear without DAL's business, but it would get awfully quiet in Salty Lake and there would suddenly be a lot of extra CRJs and pilots. We have also seen how well regionals operating aircraft on their own, without mainline connections works (see: XJT).