Can Cityjet hold on at London City? With BE (although it seems their loads aren't too good so far, even if it is a bit soon to make a judgement IMHO) in there now and BACF taking both of them on Cityjet seems to be the loser as there isn't much to differentiate them from BACF whereas BE offers lower fares.
Could Cityjet make a move so that their main operations are not at LCY? DUB? more from CWL? MAN, EDI, NCL?
Not that I know of many/any untapped or underserved routes that could be operated apart from a few EU routes from NCL. I dunno what the demand for routes is out of the others that could be operated. In the case of NCL though, Berlin, Munich, Milan, maybe Madrid, Bordeaux? Norway routes and Frankfurt etc. would be better off by SAS/LH