New Skulls Coming to Halo 3?

According to rumors started at PAX, the build shown to folks who attended contained several achievements that were not a part of the original Halo 3 release.
30 New Achievements to be exact.
Among the newly added achievements are Six New Skulls. That’s right. Six New Halo 3 Skulls. Whether or not they’ll be like traditional skulls is still up in the air (especially considering that these new skulls seem to be associated with multiplayer maps rather than single player maps) — and there are no details on whether or not they’ll be used in campaign mode to add special effects to ordinary gameplay.
Whatever the case may be, we’ve updated our Halo 3 Skulls page with the new skulls, and will be on the search for them as soon as they are made available. During our search for the IWHBYD Skull, we ended up with over 600 posts in a massive hunt for the location of the best-hidden item we’ve ever seen.
Will you be there when we search for these skulls?