As I mentioned, just put your Denon on Dolby Digital Pro Logic IIx and all 5.1 content will be in 7.1. Problem solved.
But that is for matrix 7.1 and not discrete. I'd rather let the AVR choose the content audio provided by DirecTV or a Blu Ray disc, even in 5.1 vs. a simulated 7.1. More recent Blu Rays are coming out with discrete 7.1 audio (The Avengers as an example) so true content is slowly coming. Back to my original question, I was just curious what the H34 may be plumbed for assuming DirecTV is possibly planning for future audio enhancement similar to when 5.1 was initially rolled out.