Mac OS X Netbook Compatibility Chart
gadgets.boingboing.net
gadgets.boingboing.net
Not covered on the chart, but apparently also variable: audio in, power management/fans, OS update success, two finger scrolling...
On the other hand, I just recently installed Leopard on my January 2003 model PowerBook, with an 867Mhz processor and I'm entirely pleased (to put it mildly) with the performance, so I can't see these faster systems having any trouble.
Yes. The Atom 330 (Dual core, hyperthreaded 1.6GHz atom) I use builds code at about 1/4 the speed of a 2.4GHz Core2 Duo (two cores, no hyperthreading) I previously used.
Irrelevant information: avoid the 330 boards with the 40mm 7200rpm fan on the heatsink. The fans are loud, awful, and will fail causing mayhem. I do not believe there are currently alternatives. I pulled the dead little fan from mine and mounted a 120mm fan over the heat sinks and just flood the board with air. I will buy another, but not until they get rid of the 40mm fan.
(+)Not that it was ever really true, but it was an accurate enough measure for most normal people talking about x86 processors for a few years. With the glaring exception of the Celeron - same speed, yet cheaper and less performant.