This is not a lack of disclosure, ALL devices, including PCs, have been stereo only since Netflix started. It wasn't until they released the update to the PS3 earlier this year that 5.1 capability was even seen from them. There are updates coming for other players that are supposed to be able to add this functionality as well, but not all players will likely have this and you'll need to check for your specific player. I would expect new players coming out going forward will also either already have this ability or will have it added soon as well.
No offense, and IMHO, but that's WAY too much Sony in your signature.