The new 6.0 firmware adds support for iTunes Radio and purchases from the iTunes Music Store
From TUAW:
From TUAW:
The new firmware also upgrades the AirPlay wireless streaming feature, so you can now play iTunes store-purchased content on other AppleTVs.Apple TV 6.0 update now available, adds iTunes Radio support, AirPlay from iCloud and more
The download and install was very slow for me today, likely because Apple servers are slammed with all the other updates people are doing with new iPhones and in upgrading devices to iOS 7.