The actual date April 29, 2010 will be the date the show Flashforward airs the episode that tells all. Check it out on Thursdays at 8:00 pm.
While producers Marc Guggenheim and David Goyer don't reveal any major spoilers regarding that day in the video below, they do emphasize its importance.
FlashForward is definitely the next Lost. It is full of questions. There is a diverse group of characters, led by actor Joseph Fiennes, whose lives intersect in some way. The cast includes two people from Lost, Dominic Monahan who played Charlie and Sonya Walger who played Penny.
The story is this: everyone in the entire world blacks out for 2 minutes 17 seconds, some had visions or dreams about the future, and for some it was as if they were sleeping and they remember nothing. For those who remember, they all remember the date in their dream is April 29, 2010 and they figure out through connecting with one another how they affect each other on that day.
Some don’t like the vision they saw of their future, and some do. Some wonder if they didn’t have a dream because they won’t be alive when April 29, 2010 arrives. And some begin to wonder if they can change their future.