Good catch by Kirk McElhearn:

You’ll notice that there is no longer a Toslink (optical audio) output on the back of the Apple TV. The only option you have is HDMI; this is fine to connect to a TV or AV amplifier, but if you want to connect an Apple TV to a DAC, and then to an amp, you’re out of luck. Of course, one option is to use both: an Apple TV 3 for music only, and the new Apple TV for videos, games, apps, etc.

The TOSLINK connector was originally designed by Toshiba as a proprietary interface for Toshiba CD players (TOSLINK = Toshiba Link) but was widely adopted by the rest of the industry.

Personally, I’ve never used the optical interface on the old Apple TV. I won’t miss it, but for folks who do use optical, good to know the deal on this.