lisalisa - I've been thinking about this too, since DS's bedtime (2.5Y) has crept back to about 8pm (once we've finished the stories), but he WILL not go to sleep until 8.45-9.00.
WE moved him to a bed 4 months ago, with no probs because he started to skydive out of his cot - regularly - and we just had no choice. But that's definitely made it easier for him to keep himself awake (and us on our toes).
He gets up between 6.30-7am every day without fail, and is trying really hard not to have his afternoon nap too.
I must admit that I'm grateful for the longer lie-in in the mornings. When he used to be put to bed and sleep at 7pm (in his cot where there were less distractions), our day used to start by 5-5.30. So there's no more sleep going on now than there was then - just at more social hours I suppose!
So this report worried me too - similarly to your childrent, DS is clearly not getting nearly as much sleep as the powers-that-be have decided that a child of his age needs, but what can I do about it if he will not go to sleep?