I played with a 10" or 11" widescreen Hackintosh today. Don't remember the brand (was not a Lenovo, Asus, Dell...) but it ran leopard better than my G1 Macbook, had a 1.6 GHz Atom CPU, a regular 2.5" Hard drive, built-in camera, gorgeous display and 2 hours battery life. Oh and 3 USB ports, VGA, (no firewire), bluetooth, ethernet and a card reader. The keys were normal size except the punctutation keys. Think 12" powerbook in terms of width, but much less height (widescreen). Guy told me he paid 350 Euros for it. Even Photobooth worked.
So... yea. I totally want a super small Mac now. Not thinner, smaller footprint. My Macbook (black) feels huge compared to this thing. Steve Jobs himself admitted they were having ideas for Netbooks, so it makes sense to do some testing now.
Combine the Macbook Air's logic board (tiny), an Atom processor (low-power, medium performance), Unibody enclosure with maybe 1.5" thickness, 2.5" hard drive, glass trackpad (saves a lot of vertical space since you don't need the 1" wide button) and you got yourself a great little machine. Make it work with the Macbook Air's superdrive, too.
Think EEEPC, but with an actually usable display, aluminum body and a worthy operating system.
Let the mockups begin!
EDIT: The hackintosh I played with was indeed an MSI Wind:
Here's one running Leopard:
http://gizmodo.com/5020490/msi-wind-running-mac-os-x-thinks-its-a-mac-pro