I'm also using Mediaportal, I haven't seen any plug-in that make 2-way communication possible. There is a tcp/ip plug-in for Mediaportal to send commands one-way. I use girder for this instead and it works great.

Sure, it would be fun to have a 2-way script for Mediaportal but I don't think it's that useful for me. I use SlimPronto and Squeezeboxes for music, this is a 2-way solution where one has songlists on the Pronto screen. I believe that this is a better solution for music compared to Mediaportal, especially when playing music in several rooms.

I use Mediaportal for TV,movies,pictures but not music. So the projector is always on when I use it and it's easy to navigate with only one-way capabilities when looking at the screen. It could look nicer on the Pronto if one could know what module that is used at the moment in Medialportal, I don't know if one can get that information. I would for example like to show the TV-logos on the Pronto screen when in the TV-module. But this question should maybe be directed to the Mediaportal community instead.