With regard to the low uptake of Linux on netbooks, I checked prices on Dell's website about a year ago. In several cases, the same machine cost more with Linux than WinXP. In another case, the Linux netbook was only offered with 8gb of flash storage while the Windows version was available with real hard drives.
They were also hard to find. For reasons I don't understand, they don't simply offer an operating system option when you're custom-configuring the machine. You have to go looking for it.
The same issues won't affect smartbooks.