Your Wikipedia article link doesn't directly address this. It points to several other documents though:
A 2000 ZDNet article by Duncan Campbell:
http://www.zdnet.com/article/echelon-world-under-watch-an-in...
"Under a secret agreement signed in 1947, called UKUSA, the English-speaking countries agreed to share responsibility for overseeing surveillance in different parts of the world."
That doesn't tell much. But this does:
"On 6 September 1960, two NSA defectors held a press conference and revealed the worldwide scope of NSA's activities:"
"'We know from working at NSA [that] the United States reads the secret communications of more than forty nations, including its own allies... Both enciphered and plain text communications are monitored from almost every nation in the world, including the nations on whose soil the intercept bases are located.'"
It also discusses the Church Commission hearings (1975).
I'm not sure how I'd classify this, but I see general awareness as being vastly greater. And as someone who's been paying attention to this story for a long time (15+ years), it's news to me.
http://www.nytimes.com/library/tech/99/05/cyber/articles/27n...
I guess widespread speculation that avoiding domestic surveillance laws is one of the things done with the system isn't the same as knowing that it is going on, but my point was that the widespread speculation had proceeded Snowden by quite some time.
From your NY Times article (published May 27, 1999):
Until last Sunday, no government or intelligence agency from the member states had openly admitted to the existence of the UKUSA Agreement or Echelon.
The mutual surveillance / legal evasion possibility appears to be suspected but not demonstrated. Again as with much else, what Snowden's done is to specifically document such activity. Which is of and by itself a material distinction.
European Parliament officials have also expressed concern about the use of Echelon to gather economic intelligence for participating nations.
And:
While few dispute the necessity of a system like Echelon to apprehend foreign spies, drug traffickers and terrorists, many are concerned that the system COULD be abused to collect economic and political information.
(All-caps emphasis added -- minimal HN formatting options have their drawbacks.)
So, I'll maintain that the documentation of such abuse is a New Thing.
