Emptris might not be possible just yet because AFAIK the only method for getting user input is currently a blocking call. (mlord, correct me if I'm wrong.) bmihulka's Emptris code requires non-blocking reads.

However I'm working on a project which should be a fun passenger-seat diversion and doesn't care if the reads block. A very initial test using the userland ioctl()'s looked promising last night. I don't have a timetable for it just yet but this hijack interface is making my job much easier.

Once polling input reads are available in the hijack patch, I suspect the amount of changes needed to get Emptris hooked into it are very small.