Brick Top - neither. The airlines are waiting for a plastic version of the 737, or A320, with 25% greater efficiency than the current generation aircraft. The engine manufacturers are starting to get spun up for this next battle ground as well. The 787 and A350 are almost here. The 737 replacement will be next.
The CRJ has a CRJ cabin and as you mentioned the E jet is nice, but not even a MD90, or 737N on a CASM basis & the majors are not going to let that E airplane be outsourced with more than 70 seats.
Airlines can not play the bankruptcy game due to the condition of the capital markets - so there will be no more bankruptcy court contracts. The next airline that declares, is gone.
You are completely wrong about "select few regionals being on the right track to become legacy carriers." For starters they lack their own brand, marketing, ticketing, marketing and infastructure to perform these functions. At best, they are aircraft and crew leasing companies with equivalent stability.
Since you think airlines are a "matter of time issue" tell us what the future holds? With $3.00 a gallon jet fuel making pilot salaries less of a factor and quality control more significant - the matter of time might be the obvious answer of airlines performing their own damn flying to obtain better quality control. (and I don't mean lousy pilots - I mean issues like fuel conservation, adherence to strict flight planning and limits on APU use to save gas)
Just my humble opinion.