Since Marty O'Donnell just posted a version of the Halo MWNY trailer from 1999, (view it here: https://www.youtube.com/watch?v=XL0hrSSUpHw ) I thought I'd splice together a side-by-side comparison of that version and the one from Bungie's own YouTube channel, which I remember as being the version actually shown to the MWNY audience and captured in multiple shakycam videos.

Bungie's version is on the left; Marty O'Donnell's version is on the right.

These appears to be slightly different performances of basically the same demo, but when you sync the two copies to the music, some of the edits aren't in the exact same place, and there are a few segments that are slightly different.

There's a graphical glitch in Marty's version when the Spartan first emerges into the outdoors-- some of the polygons that make up the tunnel walls become transparent briefly. There's also a different camera angle that shows multiple flying objects over the water. These appeared briefly in the official version and were never positively identified; perhaps they were an element removed from the game before release?

Finally, the Bungie flag at the end of Marty's version has a glowing Apple logo on top of it.

You can see one of the actual shakycam videos of the trailer as shown to the MacWorld crowd here:

http://rampancy.net/video/media/26/05/2009/Halo_Sneak_Peek_MacObservers_...