7.1 analog is not SPDIF - that is the digital format used by coaxial and optical.

The reason I suggest using both analog and digital connections is this: CD and DVD can use SPDIF (PCM stereo, Dolby Digital, and DTS have been transmitted this way in home theaters since the 1990's), but SACD, DVD-Audio, multichannel PCM, DD Plus, Dolby TrueHD, and both forms of DTS-HD require either HDMI or a multichannel analog connection. As a result, you really ought to have 7.1 analog hooked up between the BDP-83 and the 990 if you want to get the most from Blu-ray, SACD, and DVD-Audio, but you can just use coaxial or optical for CD and DVD. In most cases, I recommend using a digital connection for both of those formats, but the BDP-83 has such a good analog section that many folks are using 7.1 analog all the time.

(By the way, my HDMI FAQ goes into a bit more detail on why the audio limitations exist and what the different versions of HDMI mean. You can find a link in my sig. It includes a brief rant about HDMI licensing, but I recall writing a more specific rant about HDMI v1.4 recently, probaby in a 997 thread.)