Daniel (Chelsea) Manning, David Weber, Gina Grey, the recent Secret Service harassment whistleblowers, etc.
Few of them have the press that Snowden did, but Snowden isn't an isolated whistleblower. That said, seeing the lives that Manning and he have been relegated to post-whistle, I'd be surprised if the current administration hasn't scared off a good bit of would-be whistle-blowers from doing so in the future.
It isn't clear to me that he meant "trend of whistle-blowers" to mean "whistle-blowers inspired exclusively by Snowden". Both Snowden and Chelsea Manning (who previously went by Bradley, not Daniel) are a part of the presumed trend.
According to an attorney for the Government Accountability Project, they've been going there. I like her line that "Courage is contagious."
http://abcnews.go.com/blogs/headlines/2013/10/more-nsa-leake...