The Daily Telegraph talked to the Fantastic Four cast while in Sydney for the premiere and they mentioned their sequel deal which spans three movies:
“From the first day of pre-production to the last day they can release the third film is 12 years max.”
“Bloody hell, The Thing’s going to be walking around with a cane,” Chiklis laughed.
That full article is up at the link above. Meanwhile, ‘GeekgirlLA’ sent in this new UK poster for the film:

Source: Superhero Hype!