The '800 pilots required in UK in 2005' figure came from the BALPA employment symposium held last month, and is reported in BALPA's magazine, The Log, this month. As I'm sure you are all aware, as unemployed pilots you can join BALPA as associate members at the rate of £24 annually, and thus have direct access to this kind of information.
That number of 800 does not refer to ab-initio entries into the airline business, and includes a fair few jobs for those with some experience. My best guess is that roughly half that number will come from the fATPL brigade, some of which will inevitably be supplied by CTC.
There is not now, no will there ever be, a shortage of new pilots. There is often a shortage of experienced pilots, as is developing right now. What is experienced? Over 5000 airline (or around 3000 military) hours with type ratings on appropriate aircraft.
Scroggs