Things that come to mind:
- work when you don't have a network connection
- store a sizeable amount of media to entertain you while on an airplane
- use 'skype' and several hundred thousand open source packages
It does boot slower, but I find it hard to benchmark software that hasn't been released against software that does exist.
I wouldn't be sad one bit of google threw their weight behind linux adoption, for them to go and launch yet another OS to fragment the market is not what I was hoping for.