I recently fell into a deal on one of these recently after upgrading/trading in my old Airport Extreme for a TimeMachine. It will be a while before I get it running, as it will require some rethinking of my currently very basic video system (i.e. 2 channel audio only)
At the moment the sole source is Motorola HD cable box, with variable audio line out direct into small Rotel stereo power amp. To provide signal switching and control in a single component, I may need to break and buy an AVR - I'm thinking something like a small Denon would give me all the flexibility and power I'd need.
For the most part I don't anticipate buying video content from iTunes - the ATV would be mostly for slideshows of family photos, etc. The local cable provider's PPV does a good enough job for our viewing habits, and if you wait long enough a lot of new titles come free in the premium package for which we're already paying - within the past 6 months I watched for free Watchmen, Avatar, District9, too many rom-coms to remember (or be embarrassed to name) and lots of HBO. It takes a lot of content to fill the 1TB outboard drive, and they don't have expiry dates.
So back to the main question - does anyone have experience with this latest version of the ATV? I'm wondering specifically about any difference in quality of audio from iTunes library between the HDMI and Toslink outputs.