Zach Braff has not died. The Scrubs actor was, however, victim of an internet hoax on October 12, 2009, in which a faked CNN-like web site claimed that he committed suicide in his home. The rumor spread quickly through Wikipedia, Twitter, Facebook and other sites.
Braff posted an amusing video on YouTube in response to the hoax. It can be viewed here: http://www.youtube.com/watch?v=n3j4PJkkvUs
From Braff's Facebook page:
"Hi. I'm very much alive. Total internet rumor. Amazing how fast one douche can spread a lie. Be careful out there on the internets friends. Please spread the word... Video of me holding todays paper to follow... Love, zb."