While it would be nice if Apple released a small, light and cheap netbook, it doesn't appear to be likely any time soon.
Not only is Apple not announcing any new hardware this year, when asked about netbooks during November’s Q4′08 earnings conference call Apple CEO Steve Jobs told analysts that the company was taking a “wait and see" approach. Jobs also said "we don't know how to make a $500 computer that's not a piece of junk; our DNA will not let us do that."
And let's not forget that Apple already has a pseudo-netbook in the MacBook Air, and that it doesn't release new notebook hardware – especially in an entirely new category – but once every decade or so.
If you can't wait for Apple to make up its mind you can create your own Mac OS X netbook today courtesy of a DIY tutorial posted by Wired's Gadget Lab. In it Brian Chen provides explicit instructions on where to download the hacked OS and the OSX86 tools necessary to do the trick. Then it's just a matter of installing the OS on a flash drive and copying it to the netbook. For bonus points Chen also demonstrates how to swap out the netbook's Wi-Fi card with a Mac-compatible one – which costs about $10 on eBay.
Boom! MSI Wind netbook running OS X.