It was rumoured but never confirmed which i presume means it's not happening, having two fingers on the touchpad and using the pencil at the same time would be quite a feat.
as good as this bar looks, it still feels like its pales in comparison to all the other touch technology out there, a touchscreen on a mac would be a game changer yet they are very much against it.
an ipad with full utilisation and some connecting ports would equally be a game changer on the ipad pro and actually cross over into replacing a laptop territory.