Yesterday we got dropped that image of a Bungie forums search menu, which tipped something called "Halo: Reach." Such things are easily faked, and I couldn't run it down. Well, now someone's found a cache of since-deleted Bungie forum posts on this subject.
As you can see, for a brief time there was a forum for something called "Halo: Reach." A 2001 novel called "Halo: The Fall of Reach" is official, canonical, and functions as the prequel to Halo: Combat Evolved. It was also the basis for a spec script Stuart Beattie wrote for a Halo movie. Also, back in September, Phil Spencer indicated four Halo "things" were in development, two being Halo Wars, the Halo: Chronicles project said to be linked to Peter Jackson. A third can be assumed to be Halo 3: ODST, announced about a month after that interview. So is Halo: Reach the fourth thing?
The anonymous guy who gave us the search menu image yesterday claimed Halo: Reach is slated for Spring 2010, and this forum plus an ODST forum will go live June 1. Take that with a truckload of salt, but I guess it could point to an E3 announce for this Reach thing.
The site Skoar! has posted links to cached forum posts, on Bungie.net, referencing the slip-up. I took a screen shot (below) in case the cache has been cleared out by the time you read this. There's also discussion of it on Halo.Bungie.Org.
Cached Pages of Halo: Reach Discussion [Skoar!, thanks Heliophage and JihadJoe343]