Depends on your needs I guess, Macbook Air is most def not for a switcher or people who are going to edit multimedia on their mac's, however it is for people as seen as a second mac to use in the house/plane/coffee shop to check mail/listen to some tunes and browse the web.
I have a Macbook Pro as a second machine and I never take it online nor travel with it.
Editing MBP - FTW.