Does OpenBSD in Parallels count? I'm just a general UNIX nerd anyways. Don't particularly care for the current state of most Linux offerings, but OpenBSD and OS X get my motor going pretty good. I deal with Solaris and AIX all day long as well.

That said, I wouldn't ditch a MacBook (I have a 13" Black MB) or an MBP for the MBA. I said I would not. I didn't say you should not. Reasons being that my current setup wouldn't gain THAT much more storage room. We're talking one extra work shirt or something here, maybe. And as far as weight goes: Why trim 2 pounds off my laptop weight when I really should trim 50 from my body? I can do that at almost no cost.