ExpressJet will continue flying 75% of the ERJ's for CO, that's still a hell of a lot of a/c, but hopefully, they will seriously downgrade the ERJ activity at EWR to deal with congestion.
As far as I knew, they only have 3-4 gates at A(vs 24 in C), which is not nearly enough to run their RJ ops, unless they are going to bus people around, and/or take over more gates.