Today, Apple has released a new public beta for the OS X Yosemite with a new iTunes version and quite a few changes.
The Yosemite OS X public beta 2 is essentially the same as the developer preview 6 that was released earlier this week. It has several design changes, including new iconography throughout the UI (nothing you saw until now was finalized and things keep changing in the betas), new wallpapers, and some other bug fixes and general improvements.
Along with pushing the beta 2, Apple also released iTunes 12 for Yosemite. The new app has a redesigned UI that looks more flattened version of the iTunes on Mavericks and more like a new app.