Shatner confirmed during a Q&A at Wizard World Nashville Comic Con that producer J.J. Abrams has approached him about the cameo. Shatner says he told J.J. that he would be interested as long as the role was meaningful.
Shatner initially responded to the rumor on Twitter this week and claimed it was all gossip.
As the actor said during the Q&A, J.J. Abrams initially told Shatner he couldn’t say anything, and so he was surprised to see the rumor all over the Internet a few days ago. “I bet J.J. is frothing at the mouth,” Shatner said.
Although the role has been offered, it sounds like Shatner has not yet seen the script or been told what the part would be, as he noted that he had no idea how they would get him in the movie. Presumably the part would involve Captain Kirk communicating with the cast from the original timeline as Spock (Leonard Nimoy) did in Star Trek Into Darkness, but all of these details still remain unclear.
Shatner was originally written to be in the 2009 Star Trek, but his role was cut out of the movie. However Leonard Nimoy has appeared as Spock in both of the J.J. Abrams films. The scene in Star Trek 3 would reunite the original Kirk and Spock on screen.
Though J.J. Abrams is now working on Star Wars Episode VII, he still serves as producer for Star Trek 3, and it seems he will be somewhat hands on given that he is the one who contacted Shatner about the cameo.
Star Trek 3 will be directed by Roberto Orci, and is scheduled to go into production within the next 6 months.