On Tuesday, 13 November 2012 18:09:45 UTC, Dave Hill wrote:

If they are not to thick I'd have left them in the trays over winter

then taken a knife to them and cut the compost into blocks about 1 inch

square and planted those into pots before planting out a few weeks later.

Disturbing seedlings or even more advanced plants this late, isn't a great idea.
So yes, David I agree with you so long as they are not too thick.
However, I would have prefered to sow hardy annuals in their flowering positions, thinning in Spring.
For the o/p I always prick out seedlings asap, which really means as soon as you can grasp the cotyledons between finger and thumb (on no account touch any other part of the seedling, they're too delicate) - don't wait for true leaves. Loosen the compost so you have little lumps of compost full of seedlings with almost all of their root still intact and gently tease them apart and lower them into pre-dibbed holes and lightly close the holes with 2 fingers. If the compost is well well wetted in advance but not saturated you probably won't need to do much else until the little plants are growing away. This way you get almost no root damage and they hardly know they've been moved. The roots you don't want to damage are the root hairs which you can't see without magnification. These will be stripped off if you just yank the seedlings out - you certainly don't want to feel things snapping as you separate the seedlings. This should be done when conditions are favourable for continued growth. So this advice is mainly for bedding sown in early spring.
I taught this procedure to a young colleague some years ago, when he'd done the first 60 or so trays I asked him how he was getting along. 'Oh OK but I wouldn't want to do this for a living' to which my reply was 'that's just what you are doing!'

Rod