No, it will become a single airline, named (appropriately enough) ConU.
Seriously... someone hit it on the head a few posts up, United's clear investment in new seating / product for the Intl' birds means that the 3 cabin scheme is here to stay. E+ has such a great market recognition and profit potential that I can't imangine the new management wouldn't retrofit COs fleet to have it too.
I have no idea what will happen with the mileage programs and/or the clubs. Though I hate to say it, if CO sucessfully charges people a fee for upgrades then the new management would probably see that as a potential profit center too...
Whee! Prognosticating is fun!