I guess we can hope one or both stays on after December 3rd, though from comments made a long time ago (or it may have been in one of the interviews on the DVD)there may be legal reasons why they can only perform until a certain date. Also, Liam and George themselves might be ready to take a break by then. I can't imagine how hard it must be for them being at the theatre 2 performances out of every 3 for the amount of time they have been doing this now.
I doubt ticket sales over Christmas would be a reason to keep them on though. The show is always sold out as far as I can tell so it's not like they will sell more tickets that way :P
If only one did stay on, which do you think it should be?
All great things must come to pass. We know the first will soon be last and in the ground we may be lain , but a seed is sown to rise again.