Can you elaborate any further on what Athena UI will mean for MDs running UI2? We would like to retain live broadcast tv and live satellite tv with our install.
I am aware of options for connecting an raspbmc-cec myth tv front end and controlled locally, but my understanding is Dianemo will not know what is playing, cannot control it and all follow me options are unavailable.
Athena UI is built in HTML5 and so needs a device that can run a modern HTML5 browser. The way we envisage it being used is on tablets (iOS, Android and any other platform with an HTML5 browser), other HTML5 enabled devices like Smartphones, door entry panels etc etc. It will potentially be accessible from SmartTV's too if they have a suitable HTML5 browser (we have not tested this on any specific TV's yet though).
So a system could be configured with Athena UI based Orbiters on various devices that would then be used to control MD's remotely ie ste your Athena Orbiters 'room' to say 'Home Theatre' and then use an on-screen Athena UI screen to slect Live or recorded TV and have the MD's Orbiter play that content for you. Those MD's you would be controlling could be running UI1 or UI2 as all we would be doing was remotely controlling those MD from an Orbiter. You might see some on-screen weirdness when the TV attached to the MD was woken from stand-by (you'd want to turn off the 'leave monitor on for OSD' option in the Orbiter config - this would instruct the TV to go to stand-by when media playback was stopped and wake the TV when media playback started) and the MD's Orbiter started to play say some TV - but i cant see why that could not be made to work in principle. You would simply be using the Athena Orbiter to remotely control the playback of live or recorded MythTV content (which up to a few years back was something most of our installation incorporated). Whether using the UI2 Orbiter in this 'headless' role makes sense I'm not sure but I can't see why in principle it could not be done.
So the simple answer is yes you could mix the two together. There might be some rough edges to smooth out in terms of making the UI2 orbiter look aesthetically acceptable in this role though.
Give me some more background as to what your trying to achieve... as UI2 in the above config would really not be visible to any great extent.
Re Using Raspbmc-CEC (sorry I missed this part of your question in my initial response) - The way we would normally configure mythTV is to setup the Myth backend with the relevant tuners etc and use the Web based UI to schedule any recordings/repeat recording etc required. Then we would use the the MythTV web UI from an Orbiter, after first setting the Orbiter's 'room' to the room with the upnp media player located in it, to access any of those recordings stored in the Myth media library and then push that recording the the upnp device. The upnp device could be Raspbmc-CEC on a Rpi, a SmartTV or a consumer upnp media player - we don't care. The Orbiter on your mobile device would then provide the standard media playback controls - Play/Stop/Pause/Fwd/Rew etc. This potentially could be extended to LiveTV too when using Raspbmc-CEC (or any XBMC based device) but we have not tested or explored that use case yet.
Hope the above is helpful...and has not confused you further! If it has just let me know.
All the best