But we've been able to suss out a few details about Jab Tak Hai Jaan.
Shah Rukh Khan plays Samar - a role that spans two stages in his life: one in his late 20s as a London-based musician, and the second as an older, introverted and dutiful army officer in Kashmir.
According to SRK, Samar is a character that is quite close to his own personality. "Samar is a combination of angst, tenderness, anger and, yeah, he's pretty unforgiving. He's a lover who feels there is arrogance in love," says Shah Rukh.
"He feels he owns the person he loves, but then when it's needed he can show his frailty also. He accepts his flaws and his weaknesses."
Katrina Kaif plays Meera, the "archetypal Yash Chopra seductress, who is an unattainable beauty". Beautiful, talented and elegant, Kat had difficulty nailing the brief.
But with quite a bit of elbow grease, and some help from SRK, she got it right in the end.
As Kat's counterpoint, Anushka Sharma plays Akira - a 21-year-old who works for the Discovery Channel and makes documentaries.
Anushka says her character is extremely ambitious and "would do anything to make it big and realize her dreams."
The three characters and their emotions make up the entire film. In an interview before his death, Yash Chopra had said: "My film is an emotional film. It is not comedy, action, escapism... this is what we call an internal film. There are only three characters and their emotions, happiness, sadness."
Text and images: Sify.com