I've created a "proof of concept" (PoC) plugin for the Logitech UltraX Remote Control for MediaPortal. I hope that someone can use my source code (yes, it's C#) as inspiration to create a proper plugin for MediaPortal.
The status as a PoC plugin doesn't mean it's completly useless, but it does mean that you can't configure it yourself. Please download it and try it out.
I've started a thread at the MediaPortal Forums if you want to give feedback or discuss further development of the plugin.