MySpace Music has launched and it looks good on day one.  Here's what I can tell so far:

- All streaming free
- Buy through Amazon
- Up to 100 songs per playlist
- Essentially unlimited playlists
- Requires a myspace page of your own, on which you can choose any 10 songs

So it doesn't replace Pandora or Rhapsody (which I have not yet used) because it is still a pull (rather than a push) stream.  But to create multiple perfect playlists it seems great because of this:

Artists, if they wish, can now put on THEIR homepage an unlimited playlist of their catalog.

For example, check out a Pretty Great Not Good Band and listen to their whole album, rather than just the first (Very Great) single.

Conclusion: A very positive development for the streaming music fan.