LOS ANGELES TIMES [1] reports that Josh Brolin is in talks for joining the cast of MEN IN BLACK 3. Details of his role are fuzzy. The paper alludes to him playing the successor to Tommy Lee Jones' Agent K or even a younger version of the character. Star Will Smith is rumored to be returning as Agent J.
Etan Cohen (TROPIC THUNDER) penned the script. Barry Sonnenfeld is expected to return as director.
Links:
[1] http://latimesblogs.latimes.com/herocomplex/2009/12/here-comes-the-man-in-milk--josh-brolin-the-former---is-in-talks-to-play-a-prominent-role-i-men-inblack-3-the-third-instal.html