Okay while trying out some of the other myth distros to determine what was going wrong I noticed the card seemed to be sometimes in lspci and sometimes not! So I cleaned the case out and blasted the dustbunnies aside, reseated the card and tried out beta4 finally. I followed these instructions:
http://wiki.linuxmce.org/index.php/PcHDTV_HD5500and the card works flawlessly like it once did before under gentoo. Ok, minor dustbunny disaster averted, who knows really what it was as it's a fresh install of beta 4 as well. Anyhow on to ps3 fun. So in my experimentation with the mythtv centric distros I was able to get the ps3 to connect but video was always choppy, so I installed a minimal ubuntu mythtv setup using these instructions:
http://psubuntu.com/forum/viewtopic.php?t=1805edited /etc/mythtv/mysql.txt on the ps3 appropriately so it will use the linuxMCE installation as backend.
sudo /etc/init.d/gdm restart
Now at this point I got sound but no Video, I didn't get the expected smooth video like the author of the external post claims, but maybe it's because I'm reading raw terrestrial broadcast DVB? Maybe I should be transcoding these videos when they are done to a friendlier format? Anyhow, I changed the ps3 linux's xorg.conf back to the original and I could actually watch SD and HD content, but it was choppy at best, frozen at worst, though the sound came through just fine beyond any initial hiccups in both versions of xorg.conf. There's a wiki page dedicated to this topic at mythtv:
http://www.mythtv.org/wiki/index.php/MythTV_on_Playstation3That's where I found the link to the other post on the psubuntu forums. There's even information about getting the controllers to work in both wired and wireless modes. Which wouldn't it be nice to be able to use a ps3 remote as your linuxMCE gyromouse? At least another option to pursue.
So the video issue is limping at the moment but growing stronger, and could have a promising future especially if Sony decided to release some documentation. Sound is great! I'm using the optical connector and I'll see if I can't scare some surround content to pipe down the setup soon. So far as in game OS support of upnp: First off the mythTV in LinuxMCE at least shows up as a UPnP media server but results in error in all media I've accessed. I've been experimenting with media tomb and it works pretty well for pics and music, but video hardly ever works properly. I'm going to continue to experiment with different encodings and post my findings soon.