Macbooks are great little laptops, they are small, lightweight, and powerful, but still maintain a 4-5 hour battery life. I would highly recommend you buy one if you are at all interested. I would also recommend you wait till they update them later this year like this rumor suggests they might right after Leopard’s release.
Apparently Apple is looking to update the MacBook lineup along side the release of Leopard. They aren’t sure if the update will bring Santa Rosa to the MacBook line or if it will just be some slightly faster speeds.