Looks like a pretty "sound" plan.
JRemote as a zone too I hope!
Syncronized playback is still the killer feature missing. (fingers crossed)
Here's another couple ideas while your thinking ease of use, it's tied to your channel hopping concept.
1. Playdoctor/smartlist memories - A JRemote, MC & Id Feature
Ala car radio buttons (channel hop - like changing radio station genres)
Make it available as a 3x4 or 3x3 grid of buttons that popup on JRemote when you "press-hold-albumart for 1second"
2. Playdoctor enhancements - "more
from this" artist/album/genre - A JRemote, MC & Id Feature
Good for when your in random shuffle or play doctor and hear something you want to hear more of. (similar to playdoctor but more deliberate)
Make it available as a drop down under the shuffle icon on JRemote which then gives you a pop up button grid or list.
3. Playdoctor enhancements - "more
like this" - "Playdoctor remote" - A JRemote, MC & Id Feature
Currently playdoctor only works for local playback on Id/MC20, it doesn't work when playing back to a JRemote device. (JRemote as a zone might fix this by default?)
Even if you don't make playdoctor work on a JRemote, make it available as a drop down under the shuffle icon on JRemote. (currently you have to change views to list view and use the action button)
Notice a trend here? Making more use of the touch friendly JRemote and Playdoctor.