No, it is not fixed, at least entirely. I have noticed that the screen still comes on at inappropriate times, but I have yet to have an improper hang-up or facetime call. So I guess THAT may or may not be fixed. I was very disappointed to see the screen light up when the phone was in use at my ear. So I am still using a bluetooth earpiece, although I hate doing so.
I will continue to test the proximity sensor, and if I don't have the hangup problem then I can live with the unnecessary battery drain. The battery life is great anyway.