I think the reason the upsampling of D.D and dts is limited to to their own gear is that it is decoded in the player (800 v3 ,598 ,and upgraded 596) and then upsampled in the processor ( 861 v3 , upgraded 568 ).
At the moment in 596 you can already decode 2 channel Dolby tracks so there is already some DSP at work.The upgrade will probably add a lot more to enable decoding of the remaining channels.I don't think any other manufacturers use the Smartlink connection ( or similar) which is neccessary to transfer the signal for upsampling. I think it's explained a bit better in the 800 Series Version 3 info. page on their site.
Regards,
Manus

Mostly harmless. Comfortably numb.