Microsoft will be supporting the XO laptop, also known as the One Laptop Per Child (OPLC) laptop. so far, the machine only was available with linux and a user interface which, well, is not that easy to use, at least not for anybody being used to windows-based interfaces (referring to windows as the main user interface abstraction, not to Windows the operating system).
there will be lot of ideological debates whether this is somehow compromising the idea and ideals of the OPLC project. Microsoft will get $3 per laptop, which is certainly an acceptable price. on the other hand, they will of course get the opportunity to further hardcode Windows into everybody's brain as the mental model of how a computer works. not bad as a long-term strategy for ensuring that Windows will remain the de-facto standard, even in new generations of computer users.
i am definitely looking forward to installing XP on our XO laptop, the operating system so far has driven me nuts. it may be designed according to the latest breakthroughs in activity-based user interface design, but it simply is not convenient to use for anybody used to windows-based user interfaces.
i am still interested to look into how the XO could be used as an e-book reader, and what i am most interested in to look at web-based e-books. so an XO running XP and firefox 3 would be a really nice experimentation platform. on the other hand i am wondering how well the not-so-powerful XO will perform when running Windows. there definitely is a reason why they talk about putting XP on it and not vista, i guess...