Bungie's own Frankie jumped over to the NeoGAF forums to clear up some speculation floating around the new Halo 3 vidoc that was released this morning. In Frankie's post, he re-emphasizes that all the multiplayer gameplay footage was taken from the alpha build and that it is not representative of how pretty the game looks saying that,
"All of the water you saw, for example, is placeholder. No decorators are in those maps. The frame rates are all over the place. Some of that footage has correct lighting, some of it doesn't. All of that footage is olde."
He also goes on to explain that the new bubble shield and trip mine are two of the X button's deployments and are not treated as grenades as some thought. So, the beta will be graphically prettier, the frame rate will much more consistent, and the X button does indeed control the bubble shield and trip mine. Not too shabby.