Slightly different model. But iTunes match seems pretty interesting. I think iTunes needs to open up their catalog to streaming ... that would be too convenient to pass up. I love the social/discovery aspects of Rdio/Spotify/Mog. I don't like having to go find an album to download and see if I like it or find a myspace stream or something ... it's awesome to have it all in one location.
Do you think iTunes Streaming would completely negate a reason for any of the other services if they had easy sharing features within it?