Not going to say Flybe, but an operator with 70 seat aircraft could do Gatwick, Belfast and Paris twice a day. It is this type of operation that brings in the business pax that bring the higher yields, maybe something bmibaby lacked. On top of that they could do a summer service into Newquay say 4 a week along with a Jersey in the summer 3 a week supporting the GSM weekly service.
Then you have Rome which at its peak was seeing more pax than the LHR has seen at times recently. Its got to come back in some form but once a day wouldn't hurt.
MME4eva I do feel the Gatwick is needed as there is no link to the south coast but also it may give bmi the kick up the a**e on the LHR either that or push them off which may not be that bad if there is already a LGW