The LHR based crews are not presently A340 trained, thus are not allowed to crew the A340 but only crew 744s. It takes a few days to become A340 trained (less than a week); if and when CX has sufficient LHR based crews, all of the LHR flights will be operated by them ... but until then, all A340 flights have HKG based crews, while most (but not necessarily all) 744s LHR-HKG do not.

The new F/J seats are being installed in 744 and 77W; probably not in the A340s for at least another year. Interesting question which routes will get the new F (it cuts capacity from 14 to 11 seats); I suspect JFK will be the only route with new F in 2007. CX has always been slow in rolling out new cabins, and had to make the announcement early due to pressure from SQ.