If the Eee lets punters try an alternative to Microsoft and Apple's high-priced hardware/software model, why wouldn't they then think hard about the full desktop environment as well? (a low cost Asus desktop using the same applications as the Eee plus other goodies as well?)

This could be the killer-app that Linux and "Open Source" has been waiting for to get the mainstream consumer's attention.

There's nothing to stop Sony and the other manufacturers from doing the same as Asus, unless they have some sort of contract with Microsoft for operating system exclusivity (like Dell have/had).

It won't destroy Microsoft, but it will certainly worry them that a "PC" with none of their software on it is getting so much attention.