There are already mice with touch pads out there:http://www.consumer.philips.com/c/-/spm9800_10/prd/gb/
I think having the surface of the mouse do touch would be better as you get better control.
The shape in the patent application looks a bit like the Logitech M555b:http://www.logitech.com/index.cfm/mi.../5747&cl=us,en
I honestly don't know why Apple can't just buy the mice from Logitech and maybe rebrand them. Their scroll wheels are great and they are bluetooth so they connect easily to any Mac and the battery life in them is the best I've seen in a wireless mouse.
If that top shell was touch-based, the wheel isn't really needed at all.