Cyrus asked a really interesting question in HBO's forum. Paraphrased: How did Halo come to be concieved? After some discussion, Ragnarok raised the thought that maybe Matt would be able to shed some light on the issue. Here's what Matt had to say:

The initial idea was to do something like Myth but with a futuristic science-fiction setting. This was known, around the office, as Armor. There was a little test the team worked up and showed the rest of the company, involving a bunch of little marines running, jumping and cartwheeling in the surf, but the concept didn't last much longer than that. Rather, it didn't take much longer for the concept to be modified and ultimately transformed.I don't think you could trace it to a specific moment, but I think the change from RTS to third-person shooter came from a combination of Jason's desire to throw curveballs by not working on the same sort of game twice in a row, and the giddy feeling one got when zooming the camera in all the way on Armor's protagonists and realizing they looked even cooler close-up.-Matt

Some story! We've heard bits and pieces at different times but this is one of the most complete explanations thus far. Armor had been discovered last December as having been registered by Bungie at the US Patent & Trademark office and was one of the earlier names for Halo. Thanks Matt!