Thanks for that link spainlads - it was very informative. Michael Apted says he will continue making them as long as he lives, so as I've said before it must be due this year yes?
Further to my answer above , I've since read that Michael Apted has been asked about this , and has said that as long as he can get enough of the people involved willing to do it ( and he thinks he can ) then yes he will be doing 49 up. I also read that all the previous episodes from 7-up onwards are now out on a DVD box set called The Up Series but, they don't seem to be available in region 2 (i.e. U.K.) format yet.
I too saw the last instalment in 1998,when they were all 42.The next part should indeed be this year when they turn 49.I always look out for it,as it's a great programme,and i am the same age as the participants.