I know that the SPDIF output will only pipe out PCM, even from 5.1 AAC files, but I was wondering if anyone has hooked an AppleTV to a receiver and tried to get discrete surround that way. But if you are going to try, then you will need to try either some HD trailers from Apple's site(not all trailers have 5.1), or a DVD you ripped and encoded with 5.1 AAC.
If the AppleTV doesn't support surround over HDMI, then this product has many flaws.
If the AppleTV doesn't support surround over HDMI, then this product has many flaws.