This is great (and something I've wanted for a while). You can now manage multiple music libraries on your Mac. Now I can buy some external storage and rip all my CDs uncompressed.

Quoted: Switching libraries is simple; hold down the option key on your Mac (or shift key on Windows) when you launch iTunes et voilà, you'll get the option to create a new library or choose the library you want to load. For iPhoto users, this is the same shortcut you would use if you wanted to manage multiple libraries in iPhoto. Shareware app Libra iTunes library manager used to give users a way to do this, but it's nice to see Apple add this feature directly to iTunes (and yes, free is always better).

This looks like an interesting music service and companion to iTunes. It can watch waht you're listening to and draw correlations to unearth other items in your music library.

A pretty decent idea about why the music giants want to control their pricing.