I just bumped into an article on Tom's Hardware saying that the $35 laptop is scheduled to be available in January.
This is a great idea, not least because of the open-source system. It's not surprising to me that a usable tablet can be made inexpensively (although I suspect that there is some cost subsidy to bring it out at this price). What is surprising to me is that corporate software companies haven't been successful at stopping the open-source part of the project - the spread of the Android operating system that this will probably cause has got to be a threat to commercial OS'es.
I'll keep an eye out. If it's a reasonable price, I may even get one.