RIM slipped in some new parental controls that showed up in their latest OS leaks and now they are taking it further. They have announced that the BlackBerry Curve 9220 & Curve 9320 will be rolling out with the new parental controls built in. What is very interesting is that RIM has confirmed on their blog that:
Parental Controls is an integrated feature that provides parents and guardians simple options to help them protect their children by restricting access to specific functions, features and applications. A free download of Parental Controls will be made available for BlackBerry® 7.0 OS and BlackBerry® 6 OS next month; and for BlackBerry® Device Software 5.0 shortly after through the BlackBerry App World™ storefront.
That means OS 5.0+ devices should all be getting parental controls in the next month or two. As far as I have seen so far the parental controls make use of the IT Policy structure RIM already has in place for enterprise customers so it makes sense that RIM would be able to bring it to older OS versions. You can check out the official user guide of Parental Controls for more details.