I know two people, however, one on the Trippler and another on the Bus and they're working very hard.
That's because it's the way BA want it. They have been granting a great deal of Short Term Unpaid Leave. (the key word being 'unpaid'!) in order to save money. should they wish to increase the number of available pilots, one assumes they will simply cancel this arrangement.
Up to (and including) 2016, out of a workforce of 3700-3800, only
twenty six pilots will hit 65. In BA, virtually nobody retires voluntarily before then. Please feel free to draw your own conclusions!
Edited to add: There is an unspoken assumption in the above that 65 remains the compulsory retirement age. That may prove to be a poor assumption. Bear in mind also that the average age of BA's most senior 1000 captains is currently less than 52.