Guys, calm down! Two points:
1) Linux has many different languages available. I've never used anything but English, so I can't comment on the translation quality. Still, they're there.
2) Like alikum said, you get what you pay for. Mac users get multiple languages, but (to put it mildly) they pay a premium. Those of us who use Windows and don't need Estonian, Swahili, Russian, etc. lanquage packs have the option of saving money and going with something like Win7 Home Premium. It makes sense to me that we pay less for fewer features that we don't need!
Re: the article itself - too bad MS doesn't simply disallow the installation of the MUI on non-compatible versions of Win7. I'm sure a version check would be easy to implement for them...