Waiting for this as well.

I hate to admit it, but Microsoft has a great solution for this. https://fss.live.com/ Parents can use their existing passport accounts add the kids own hotmail.com or live.com email adresses, and then the parents are in control of every contact they can receive or send from. The kids can make requests, and then parent can grant them. It also works for Windows Live Messenger, only the contacts the parents approve are allowed to talk. I have been using it for my 10 and 8 year old. Works great. Even on Linux. You just have to live the stigma of giving your kids hotmail.com accounts.