The coaxial audio connection will carry only the core DD and DTS tracks - it will not allow access to the new audio formats. To get those, you will need to have a player with onboard decoding and a multichannel analog output. Since the Model 950's multichannel analog input is 5.1, you have a few extra options. For example, Panasonic's BD50 is being replaced by the BD55 (in part because the BD50 has a 5.1 analog out instead of 7.1) and might be available for a nice price in the coming weeks as BD55's start to ship.

Oh, there's a link in my sig to an HDMI FAQ. You may or may not find it of use when delving into the world of Blu-ray and HDMI...