[Update - XdM] This story originally, and incorrectly, stated that Halo Anniversary would see the return of the Magnum weapon from the original Halo in multiplayer via a title update to Halo Reach. What 343 Industries is actually doing is tweaking the current handgun to bring it as close to the original pistol as possible. Specifically, 343 told me at Halo Fest that the weapon will return to its three-shot headshot glory.
A number of other tweaks will be made to the game in stages, including the ability to ship away at an Armor Lock's energy by firing on locked Spartans and the removal of the Lock's ability to remove grenades that have stuck to the player. The complete Title Update for Reach is set to launch later this year.
[Original Story - SW] As part of Halo Fest (taking part inside PAX 2011), Microsoft and 343 Industries revealed two more bits of Halo goodness on top of the Terminals and Forza 4 Warthog announcements. Both Halo: Combat Evolved Anniversary and Halo Reach will feature a fan-favorite classic weapon, and Anniversary is adding 3D support to its feature list.
Probably most exciting to long-term Halo fans is the return of the Magnum pistol. It will be included in Anniversary, and come via a title update to Reach. It will only be included in special-made "Classic" playlists, but some magnum is better than no magnum. The October update will also bring balance tweaks, like basing the Armor Lock on the amount of remaining energy, shortening the Active Camo duration, changing sword blocking to only work with other swords, and giving reticle options. Plus, players who only have the 4GB console will finally be able to use Campaign and Firefight matchmaking.
Also announced, Halo Anniversary will sport a new custom-made top-and-bottom 3D technology, compatible with 3D TVs. Attendees of PAX can see it for themselves at the event. Epic Games recently announced 3D support for 360-exclusive Gears of War 3, so it seems like Microsoft is trying for feature parity with Sony's 3D push.