Rdio's totally redesigned browser and desktop app interface made what was already basically the best-organised streaming service even cleaner. Ostensibly, it puts albums artists and songs first, but really it's putting you and your experience at the top of its priorities list. Now it's available to everyone.
The interface looks sort of like a cross between iTunes and Facebook's Social Graph -- in a good way. Playlists and other organising categories are on the left-hand side, and your friends and their activities are on the right. You can drag whole albums into playlists or messages to friends just by dragging the album artwork, and the album pages themselves remember where you were, so, theoretically, navigation should be easier.