Until iTunes Match allows you to stream any music from the iTunes store regardless of whether you have previously bought it, it will remain a very different service to Spotify. The article is a bit misleading in that way. Spotify is an all-you-can-eat buffet, iTunes Match is a well-stocked fridge.
I can see the advantage for people with not enough storage on their phone though.
I really hope Apple puts out a streaming service like Spotify at some point this year.
Of the services currently available though, I much prefer Rdio. But if Apple were to have a service available on iOS, OSX, and AppleTV I am pretty sure I would switch.