Word is always going to get it out... it is a PUBLIC BETA TEST, there are no NDA's... just rules made up by one website.
I know there's some sensitivity here when it comes to talking about DBSTalk, but to be honest, the rules they have that CE should be limited to the CE forums make perfect sense to me. Consider what Engadget did today: they said in their article that if you are in the test group, restart and hit 0,2,4,6,8. That's it. They didn't add anything else to the article, explaining that test software is only available for download during limited windows, that test software could be unstable and cause you to lose recordings or other settings, that DIRECTV customer service doesn't officially support anything other than the national software, etc.
The thread in the main forum here indicated that one person already did 02468 and just got the national software. How many folks who read Engadget also tried it? How many of them called up DIRECTV to ask about it? How many of the Engadget readers will look for information on the download windows, find it, install the CE software just to get the GUI, and then be upset that something went wrong and call DIRECTV customer service because they don't understand what they are doing?
As you state, word will get out, but the rules meant to contain the discussion of CE to those who understand what test software is, who understand what testing is about, well ... I think that's actually a good idea. I think of it this way: I may tell my 74 year old mother that HD GUI is coming, but I'm not going to drive to her house before a CE window and install test software on her receivers, and I'm not going to tell her how to download it, knowing full well something could go wrong after I leave. I know my mother, I love my mother, but she's not someone who can handle technical problems and I think there are more DIRECTV customers like her than there are like the CE testers...