Halo developer 343 Industries is working on a high-definition remaster of Halo 2, according to a rumor in the latest issue of Official Xbox Magazine.
Like last year’s Halo: Combat Evolved Anniversary, this update is said to be called Halo 2 Anniversary.
Halo Anniversary launched ten years after its initial release. If the pattern continues, we could be looking at a 2014 release for Halo 2 Anniversary. (Though, I personally doubt an HD update would take that long to develop.)