1500 sounds on the high side to me; I'd be happier to believe a figure of 5-700. However, I'd agree that no more than a third of fATPL graduates get a job in their year of graduation - and it's probably less than that. As for retirements, 100% of all currently flying pilots will retire! The proportion of the total that retires in any given year will be roughly the same; any peaks and troughs will be minor and (despite the claims of some) will not result in recruiting bonanzas for fATPLs.
Will air travel double - and over how long? I don't know, but watching the environmentalist and Nimby campaigns against all major infrastructure developments over the last few years leads me to believe that it won't expand in UK, or the West generally, as quickly as the analysts suggest. There's plenty of scope in Africa and Asia - but then they have plenty of people of their own to train and take those jobs, and you can be certain that they will want their own people to take those jobs!
Overall this is a good time for aviation recruiting in UK, but MyTravel's decision to ditch its Boeing fleet and personnel shows how precarious things are, even in the good times. The Times today has an article debating the effects that a property 'crash' would have on our economy, and the author reckons that such a crash is coming. I can tell you that one of the first things to go when people feel their wealth decrease is leisure spending. That translates instantly into fewer holidays, and thus fewer flights - and suddenly we're back into downsizing fleets and laying off (or at least not replacing) flight crews. It takes so little to reverse good fortune!
Don't expect nirvana just yet!
Scroggs