I certainly wouldn't count on this capability, though; it varies from TV to TV and is never documented AFAIK. For example, my older Sony (2008) would pass DD5.1, but it wouldn't do DTS, which foiled my plans to use it as the HDMI switch for my pre-HDMI AVR. Current Panasonic plasmas pass neither from HDMI inputs.
That's exactly my point. There is no sense to try use your TV as a HDMI switcher (many ppl actually tried to do this way) which doesn't work correctly in most cases. This feature of passing DD 5.1 is virtually worthless. Vizio tried to marketing on this and gave up. Sony probably will too. The reason is majority of the BD releases today are DTS-HD MA. There is no DD 5.1 audio tracks on those discs.