I thought about using the regular RCA left and right outputs. I am using XLR outputs to my amps so the RCA outputs aren't being used. The downside to that is the volume control of the 886 will effect the volume of the LD. In other words the 886 will be changing the gain. Also, since I have a 7.1 setup and the left/right channels are crossed at 40hz I wouldn't get the full signal without having to change settings every time I use the headphone amp.
I am not using Zone 2 or 3 but I am almost positive they only work with analog stereo inputs. Which means I would have to run RCA cables for them to work. Maybe there is a setting in the 886 that makes the tape monitor output work with digital inputs but I doubt it. I will RTFM tonight and post on the 886 thread on avsforum.
I mainly use the Oppo for listening to music but I do listen to a few concert HD DVDs and can stream music from my computer using the cable box. Being able to use all sources without having to change any settings would be ideal. I am getting the feeling it won't be that simple. I could always use the headphone output of the 886 to feed the LD but obviously that would give far from ideal sound quality.