I always check out the Mac Buyer's Guide
. It tracks the time between updates of all the Mac product lines and makes a suggestion on whether now is a good time to buy.
Looks like Macbook is at the bottom of the list, meaning the next update is likely 120 days away, assuming the average refresh time holds. They recommend now is a good time to buy.
The world needs more Canada.
Macbook Air 11" Core 2 Duo 1.6 GHz, 4 GB RAM, 128 GB flash HD, 10.7.2
iPhone 4 32 GB, iOS 5.0
iPad 2 white 64 GB Wifi only (all over tethering, man), iOS 5.0