The latest issue of Official Xbox Magazine UK says that 343 Industries, maker of last year's Halo: Combat Evolved Anniversary (and, of course, this year's all-new Halo 4), has similar plans for Halo 2.
"Following the success of remake Halo Anniversary, 343 Industries has now started development of Halo 2 Anniversary," the magazine says in its rumors section. No sourcing or other details are given.
Asked about the rumor, a Microsoft spokesman told Kotaku: "Our focus right now is on developing Halo 4. Beyond that, we do not comment on rumors or speculation."