Definitely not a windows killer, but I can imagine a lot of businesses and schools getting in on this. After all, Windows professional edition + office professional = $700.
No it won't make sense for everybody, but it makes a good bit of sense for businesses and schools, which is the demographic that makes the most money for Microsoft anyway.
I'm sure the "windows killer" was just an exploit to get you to actually read the article though. The only real "windows killer" will be windows.