They did announce the "Master Chief Saga" slated for release on XB1 that will include "remastered" versions of Halo 1, 2, 3, and 4, and still undetermined whether or not the collection will be released to the 360 or any other platform (so no idea if it will be on steam). Wars, Reach, and ODST were left out because they weren't centered around John. So I guess that's as close to a "Halo 2 Anniversary" as we're getting. Didn't mention whether or not there would be any new content or anything to tie it in with 5 or expand on 4, so it's still up for speculation on whether it's just going to be a simple graphical upgrade or if, like CE Anniversary, new things will be added (terminals and skulls) and/or bring fresh content to current games (like how CE added Multiplayer and Firefight maps to Reach). Personally, I would really love it if this meant bringing the original Rogue to the new line-up. I really, really don't like what 343 did to it.