Tuncer Deniz at Inside Mac Games has put up Part 1 of a series on his experiences at Bungie. Above all, he talks about how Bungie was always trying to do things differently:

After Marathon, Jason [Jones] started working on Myth and once again, his vision was to create something different. At the time strategy games like Command & Conquer had come out and were the rage of the computer gaming world. Companies like Ensemble created clones like Age of Empires. Jason wanted to build a strategy game but didn't like those types of games because he felt resource management was boring. During the early development, many of his co-workers, including myself, tried to convince Jason that Myth had to have resource management. Jason insisted there be none. He wanted to build a game that you could play online for 15-20 minutes, not one hour.

I think the success of the Myth franchise bore out that Jones' call was the right one; the focus on battlefield tactics over resource management made Myth much more of a chess-like game; simultaneously far more accessible to the average gamer, and yet tactically even deeper than some games with advanced resource management aspects.

It's understandble, given the runaway success of the first and second Halo games, that Bungie would be expected to round out the trilogy and finish the story. In a way, it's what Microsoft bought Bungie for. However, to some extent I think the real benefit will come when that debt to the platform is paid off; when Bungie has delivered its third smash first person shooter hit for the Xbox 360 and can get to work on something different again, this time with access to far more resources than when Bungie was an independent developer/publisher.