In August there were social media reports floating around that showed Sacha Baron Cohen filming something in Los Angeles. This, of course, was very vague, but it was still something that may have caught your attention. After all, it's not like it's good for business if people know he's up to something.
Now, a few weeks later, Collider is reporting that Cohen has already shot a sequel to Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan, and that he's subsequently screened the movie for some people in the film industry. Collider writes that it's their understanding that what was completed is a feature film, and not part of a series or ad campaign. Adjust your expectations as you see fit with that info, but it may be best to wait for updates.
Collider concedes that details regarding the plot are largely unclear at the moment, but that the titular character's "no longer the little-known Kazakh TV personality he played in the original 2006 movie." Because of that things sound like they've gotten very meta, as Borat now needs to go "undercover" for interviews because the public's aware of who he is. A source quoted by Collider says the film is "Cohen playing Borat playing Cohen," but after they wrote that a separate source contacted them to say that wasn't an accurate description, while still acknowledging the existence of the movie.
In addition to the plot being vague with contradictory descriptions, it's also not known what studio is backing the project, or who's directing it. Also it's not clear when it'll come out, or in what format it will be released on.
Anyway, this has been a long time coming. The original grossed $262 million across the globe when it was released in 2006. It also opened the door for other Cohen-starring films, like Bruno and The Dictator. Those combined to gross well over $300 million.