Jean: you can do the "borrow and cancel trick" and avoid waiting around. This assumes you have a January Use Year---it might not work for other use years, so be careful.
All you need to do is make a reservation for the same amount of points as the December reservation you want, anytime in the next 90 days. Then, cancel it. The borrowed points are returned to your account as Cancel points. Because cancel points can be used for Standard reservations, they can be used for late December reservations later this month.
A competent VC will help you do this, if you ask nicely. If you do everything in the same day, it costs only one transaction.
The other way to accomplish what you want is to credit pool the 2010 points. They become usable for three years from the day you enter them into the pool---so, if you did it today, they'd be good from 2/13/09--2/12/12, and you can use them for the December booking at the 10-month window. A slightly less-competent VC will suggest this route. It costs $39 to place points in the pool. This is also subject to the pool "not running dry", but this early in the calendar year, that doesn't seem likely.