Meh, NDAs. It's just a matter of time until Canon Rumors establishes some well-placed snitches. NDAs require evidence to enforce. Under US law, Canonrumors would be immune from subpoena due to first amendment protection for the press. Pretty difficult for Canon to make a case against an individual, particularly if information has been disseminated to hundreds of people. Canonrumors is a relatively young site. I would surmise that over the next few years, rumors will become increasingly more reliable, particularly as individuals who claim to be well-placed or well-informed are vetted and corroborated.
Let me be clear, I'm not recommending violating an NDA, I'm just saying that Canon would likely be unable to take action under the UTSA.