If BA could get the approval for holding that number of slots a LHR, it could be the catalyst for a large and BA led change in the UK. I'd imagine it would give BA the excuse to all but relieve itself of LGW ops, retaining maybe some key European business routes and the 777 Caribbean services. I'd imagine that Baby would be wound up along the way. BA may also want to capitalise on it's Flybe stake and offer them Regional and their current LGW shuttle operation.
If that were to be the case, then I'd suggest UK aviation will be dominated by BA & easyJet, is that a good thing?