MacBook Air is enough for a work machine
Not MBA-related, but for MBP machines you can use an OptiBay bracket to pull out the optical drive and replace it with an SSD or HD.  Couple notes on that:- The OptiBay is $80, but includes a USB enclosure for your SuperDrive to turn it into an external drive: http://www.mcetech.com/optibay/- Cheap clone brackets are ~$20 on eBay, work just as well.- The original HD bay includes a sudden motion sensor to park the heads on a drop.  Ideal setup is to put an SSD in the optical bay and a HD in the internal.- Battery life doesn't seem affected by two drives.  I suspect cpu/video/display power significantly outweighs power from an SSD.- The optical bay is 3 Gbps, the HD bay is 6 Gbps.  Don't bother with the extra cost of new 6 Gbps SSDs if you put it in the optical position.- If you do this on a new machine, do your boot camp install before you remove the drive.  MacBook Pros have some kind of hard-wired device order that makes it impossible to install Windows from an external USB/FireWire optical drive.I run a 250 GB SandForce SSD + 500 GB 7200rpm drive.  SandForce does on-device garbage collection, which helps since OS X has no general-use TRIM support, and I do photo editing on the road so the faster HD is great.