The most notable new feature is support for the Amazon MP3 store - you can buy and download music from within Banshee - but unfortunately it's only available in the Linux build at the moment (OS X and Windows support are planned, however). The Mac OS X build of version 2 is due later today.
A few moments ago, version 2 of the Banshee music player for Linux was released, bringing with it a whole slew of new features, and the addition of an official - but alpha-quality - Windows build.