missholly, there is a waiting list from other bases within BA to go to LHR WW, however the hundreds of temps coming on line will help keep the levels of experience consistent in other bases such as LGW and over 200 cabin crew are moving up the road this summer from LGW. So transfers are being achieved.
With regards to your interest in leaving EK for BA all I can say is that people come to BA from Dubai, I have met a few.. How many cabin crew coming from BA EF, WW or Gatwick have you flown with in EK? (Just asking).
EF is a nice fleet with many, many nitestops and layovers all over Europe, as many business travellers need early departures and arrivals to and from LHR.