Alongside the iOS 7 beta 4 and iTunes 11.1 with iTunes Radio betas, Apple has provided developers with a new Apple TV OS 5.4 seed. Below are the release notes. Thanks to everyone who sent this in. 

A tipster sent in the video below showing that iTunes music purchasing has returned in the latest beta, a feature that was only available on the first generation Apple TV:

Fixed in Seed 3

• Apple TV may not connect to the Internet on first boot after an iTunes Restore when using Ethernet. • Music playback may skip over tracks when AirPlay is engaged. • AirPlay of audio from the Music app may fail to start up properly. • Attempting to delete a station in iTunes Radio may cause Apple TV to crash. • Switching between Apple IDs may cause music libraries to fail to load. • Audio volume may increase dramatically during AirPlay. • When using AirPlay to send music to Apple TV, advancing to the next track may fail. • You may notice these issues when fast-forwarding 3rd party content: • Audio continues to play while video is fast-forwarding. • Resuming playback after fast-forwarding can result in a temporarily stuck video frame. • Apple TV may become sluggish or unresponsive immediately after signing in to an iTunes Store account. • iTunes Match or Purchased music content may not be listed alphabetically. Use Search as an alternative for finding content.