Niveus have opened up a beta of their Companion software. This is a package for controlling your Media Center PC from another PC, eg UMPC. So far this has only been available to Niveus customers. I am downloading now and will have a play
Niveus Media Center Companion™ software is the ultimate networked remote control for the Niveus Media Center & Niveus Media Extender. Picking up where the award-winning Niveus Pocket Remote™ leaves off, Niveus Media Center Companion™ empowers you to take full control of the media experience by integrating remote control abilities for your digital photos, music collection, Internet radio stations, videos and more.