The decision as to whether the BA operation at LCY will become 'mainline' or not hinges on which aircraft type is selected for the operation going forward.
If it's the A318, then it will become a mainline fleet, and I can't see BA waving goodbye to the current staff, and simply 'installing' it's own. The company will have little choice but to absorb Cityflyer AGAIN, and in exactly the same way as it did some years earlier. The only spanner in the works is, how soon LCY and the A318 can be 'married'!
If however, the choice of new aircraft is the RJ85, with leases running anywhere close to 2012 or beyond, then I'm afraid to say BA will have created a very lucrative 'stand alone' London based airline, with low staff costs. So it will be management bonuses all round, and no chance of mainline access for the current incumbents.
Since the RJ100 lease 'issue' needs to be adressed fairly soon, I don't think there will be too long to wait before the writing is on the wall.