I have read several posts in the past say they have done the very thing this thread is talking about. I believe this maybe part of the trojan horse that BD has created. I have called it reverse affect as well. As a fanboy, gamer and one who enjoys movies, particularly BD, I am delighted to hear non gamers are embracing gaming as a result of originally purchasing a PS3 for BD only. It helps to support the possibility that BD and the PS3 is maybe the one and that is good for me and my wallet in the long run.
I remember one post was a guy relating how he downloaded the GT HD concept demo from the PS store. He said he was playing it when his wife heard the noise and walked in to see the screen. She thought it was actual video of Switzerland.
Once PS3 owners have that controller in hand, even to use just for BD playback, they get curious. I have to admit prior to reading some of these stories I didn't see that coming. Sony is not stupid and way ahead of many of us when it comes to marketing.