Just in case you were still wondering if Will Smith was going to be in Independence Day 2, the answer is no. Director Roland Emmerich and co-writer and producer Dean Devlin have been developing the sequel for a few years, and now it looks like the people of Earth will have to battle the aliens without Smith.
According to Deadline, "Smith informed the studio that he won’t be joining in on a sequel that the filmmakers hope to have in theaters for July 4th weekend, 2016."
Emmerich was prepared for this, and he had James Vanderbilt write two scripts, one of "which takes the battle to the aliens without [Smith's] cocky hero fighter pilot Captain Steven Hiller." So there's still a chance that the sequel will happen, and I really hope it does! I think it could be just as fun without Smith involved. I also think the movie would be just as successful.