Well.. I'm not sure that's going to happen anytime soon.
I have MameHub launched from the PC Launcher module , which works well , but I don't have a stand up cab built yet. I doubt it's a problem assigning a trackball for the gui. Point , Click and you're away. Probably isn't anything from stopping you loading skype or something at the same time. It may look a bit messy and you might have to position the windows a bit, but still possible.
There is other software for multiplayer on a cab , can't think what it's called right now though.