What has confused the issue so much for many people is that there are 2 new regulations which (because they had already slipped the date for the requirement from Oct 2003 to Oct 2004) then, until the delay of the biometric, were both due to come into force this Oct.

As Carla said most adults should now have machine readable passports (I think it might be some old blue diplomatic ones I heard which were valid for longer.
Also since children have had to have their own passports for quite a few years now, it's only the ones who may still be travelling on their parents passports who need new ones but they must be getting near their expiry date I would imagine.