Why are people so convinced that the 60mm macro will get an update with I/S? Just because of the patent?
The bigger question for me is why would someone prefer to have this lens over the 100mm macro? While I know there are cost and size advantages, I would think the not-as-pleasant out-of-focus areas, EF-S limitation (can't mount to FF), shorter working distance, and probably poorer build construction would be things you wouldn't want to give up.
It seems to me there are more important lenses in the line-up that are actually in need of an update.