I have just got a MacBook two days ago.
I'm enjoying using it.
Since I like Ubuntu, I installed it on VMware Fusion (Mac version of VMware) on it.
I still have a lot to learn about MacBook. It's different from Linux and what I'm not familiar with is how to manage applications, which you can do with apt-get, yum, etc. on Linux. Also the directory structure itself.
The next thing I do is to set up Ruby on Rails on it.
Well, I kept the promise to get one with a speaker at No Fluff Just Stuff conference last September. Of course, many other people recommended, too.