According to IMDB.com, Men In Black III will see the return of Agent Jay (Will Smith) and Agent Kay (Tommy Lee Jones) to the big screen May 25, 2012. It was rumored that Sacha Baron Cohen would play the villain Yaz, but according to IMDB news sources it is confirmed that Jemaine Clement is up to play the part. Another add to the Men in Black project, is James Brolin. Initially, the star of Jonah Hex didn't want to work on the project, but after a bit more of a sales pitch it seems he is more interested than previously and is set to play a younger version of Agent Kay.
According to AceShowbiz.com the movie will be released in 3D. While the full plot hasn't been released yet, it has been mentioned that Agents Jay and Kay will be doing a bit of time traveling in this one possibly even meeting up with a younger Kay in 1969. Should be interesting as long as Smith and Jones stay a part of the cast.
(***Sources IMDB.com and AceShowbiz.com)