So it's not really a 'launch' or a 'music service'. It's an integration.
Having said that, I think the 'listen to the same music as your friends' bit is pretty interesting.
Unless all your friends have shitty taste.
note: I do find it a technically interesting feature
That's kind of cool, so you have a group of "friends" on facebook or whatever that you use for new music discovery?
edit: the poorly implied question would be what does using a generic social network get you that an account on a targeted site like last.fm doesn't have?
When my friends post links to youtube or soundcloud it's usually only for tracks they really like. Newness is a good criteria for posting, as is good stuff you may not have listened to in a years.
You can do all this with last.fm, but for whatever reason no one I know uses it as such. Facebook, irc and message boards seem to be the best places for me to learn about new music.
You can always tune the same radio station... :-)
I know you don't get to pick the songs, but it's an easy solution.