To clarify, I'm not trying to discount the systems themselves at all. My wife's TL has a backup camera that works with her Navi screen and it's great.
What I was trying to say, though, is that we all know that the general motoring public is not always bright enough to use the tools at their disposal, so I wouldn't think this tool would be much different. It will help at first...but eventually people will just either ignore it or find another way to horribly run over shit. I see this happening more in the lower end cars which get less expensive and effective systems.