As I understand it (and please note that I have no direct knowledge of this - my knowledge of Stuxnet comes from what I read on the news), the malware contained 0days for XP, Vista and Windows 7.  There are elements in the quoted article that don't jive with other things I've read about Stuxnet.

I'm not saying the article is incorrect.  Just that what the article says is different from what other people have written about this issue.