lol. I can't believe people here are actually saying either 'buy now because there won't be a refresh until 2012' or 'wait because there will be a refresh.'
If you want to buy a laptop, think before you buy it. IF you need it desperately for some kind of project or trip, then I will say go for it. However, if you can wait, then wait. There is no real reason to hurry.
Here is a checklist that I go through if I want to buy a new laptop:
[] Do you really need a better laptop/computer? If yes, continue.
[] (If you have a computer that you use currently) Do you have any buyers willing to purchase your current laptop/computer? If yes, continue. If no, you can still continue, but remember you'll get more money out of it by selling your current machine.
[] Are there any significant difference (performance/aesthetic) that you can take advantage of? For e.g. The new 2nd gen. Core i series can do hyper threading, so you can take advantage of that if you are a CPU intensive user, such as Final Cut Pro or gamer. If yes, continue.
[] Do you have enough money to purchase the machine you want? If yes, continue.
[] Will you not regret if there is a refresh next month (even though you won't know if it's going to be any better)? If yes, buy the laptop!
The list is nothing special. Again, if you can wait, then wait. But remember, nobody knows when there will be a refresh in the future. It might take more than you expected for the refresh.