Judge it for youself: http://www.youtube.com/watch?v=ZgdUWXf8jJk
http://www.youtube.com/watch?v=_KmGeX8nyck
She says the scene was originally an idea proposed by Bob's wife, early in the series (2nd year or so). At the time, they didn't think they would ever be allowed to do it, but in the last year of the series, the producers called Pleshette, and she immediately knew why.
There's more about all the secrecy around it. The rest of the cast thought it was going to end with Bob talking to God. They didn't find out until 20 minutes prior to shooting the scene.
LOL! When I read his name its the first thing that came to mind. :)