Microsoft's partnership with Peter Jackson no longer exists, despite being a big deal when it was announced back in 2006. So what happened? As with most things, it was budget cuts.
Jackson's manager Ken Kamins told the Los Angeles Times, "They were scaling back everything, including the number of Halo games, and it just made sense at that point."

"Once The Hobbit and Tintin got going, they really cannibalized Peter's time and ability to oversee any Halo games."

According to Kamins, little progress was made on Halo Chronicles due to Jackson splitting his time between the aforementioned movies, as well as District 9 and The Lovely Bones.

Jackson envisioned Halo Chronicles as being "not quite a game, not quite a film." If it has been completed, it would have been a multi-episode, interactive series.

As it is, Halo Chronicles is gone, but Jackson still has an interest in video games. Jackson's studio Wingnut Interactive still exists, and Kamins confirmed that it's working on new projects.

"It was born out of this [Halo deal], but now Peter has people in Wingnut Interactive working on original intellectual property," he said.