This feature has been released to everyone .. something was pushed to your receiver that enabled Youtube (I don't know all of the technical details). It's apparently not working for everyone, though.
I do know that your DVR must be connected to the Internet and that the parental controls need to allow videos.
I think what is going on is that your DVR simply isn't "seeing" the servers responsible for making this work. I don't know if this is because of something on your end or something on DIRECTV's end. I'm still waiting for feedback from DIRECTV.
In any event, this is no longer a Cutting Edge only feature.
Am looking forward to you posting the feedback you get from DirecTV. As I posted the technician I talked with acknowledged there is a problem with the Youtube release and that their engineers are working on it but would not tell me what the problem is and that resetting the receiver works in some cases but not all.