What is stirring at Bungie?

Several websites are reporting that people at Bungie, the developers of the popular HALO games, are hinting that they might be announcing something at the 12th of July - at E3.
What?

Most people say that it is probably a new game or project.

Here are my thoughts.
1: It is doubtful, but it would be a big surprise if it was some kind of expansion or add-on to Halo 3, whether it's more game modes and maps for online play, or even some single-player action.
2: Maybe even more unrealistic, but it would DEFINITELY make a lot of buzz if HALO 4 was announced..
3: New MYTH game? Or maybe they are making a new Marathon game?

One thing is for sure...we will just have to wait and see!

-H