Proximity sensor still works like ass. It does not shut off if I slip the phone in my pocket, etc, causing things to get inadvertently selected.
You're pants pocket won't activate the proximity sensor, no one's will. Unless your pants are made of peoples' ears/faces. Then you have other issues.
Also, you shouldn't be getting any screen touch events in your pocket, since there's nothing capacitive in there...at least there shouldn't be anything capacitive in your pocket.
Use the lock button.