The event system in the old ANimation system had support for arguments of type GameObject. Mecanim events generalize that and have support for arguments of type Object. That means that I can pass anything in there (for example, a scene file) and make changes to that when the event is fired. Shouldn't this be reverted to GameObject only? Also, when actually trying to select a GameObject in the Event window, I can only see Assets in the Selection window, but nothing in the scene. I would expect to be able to pass any GameObject to a Mecanim event, but apparently only Assets can be passed in.