I've added functionality to cancel and move tokens today. I've also added a process variable view and task list to the process instance screen. There may be one or two other features as well.
I'm a bit hesitant on the cancel/move token functionality because it doesn't take into account the tasks that are currently pending. So you can move a token and just leave the task hanging out there. I've disabled the move button for now, but if you want to play with it, just remove the "true ||" part of the disabled="" string on the xhtml.
Let me know what you think so far. Layout is still a mess, I know, but the content is getting in there finally, and that's really the important bit.