Apple has been unambiguous about the fact that they aren't just going to plunge into the netbook market. If they ever do release a netbook, expect them to go the Sony route of denying they are releasing a netbook at all, which at this year's CES came so much across like the most fabulous guy at the George curling up his nose in disgust and shouting "I'm not gay... call me metrosexual!" at the top of his lungs. The term netbook implies cheapness, and Apple's not going to go that route.
But here's someone's optimistic imagining of what a MacBook netbook could look like. Like the Vaio P, it would have a full size keyboard, with a surprisingly wide screen. Unlike the Vaio P, though, the MacBook Mini would feature a fold down leaf for a full track pad... no clitoral nub! All with MacBook Air thickness.
I like this design quite a bit.
MacBook mini [Wired]