Small note, but some things that kind of annoy me:
1. Audio sync issues -- the mouths and the words don't line up. I may just download the video and use the Audio Delay tool in VLC to watch it.
2. Start time of the talk: in this video you've just linked, the presentation doesn't even begin till like 6 mins in. Somewhat similar issue on the original video...
EDIT: Download link for the Abrash video: http://www.clipconverter.cc/download/pwvblTMb/123146223/
Download link for the Carmack video: http://www.clipconverter.cc/download/ecJvSoeC/123169959/
EDIT: Here's the "Bar/Far" video clip that Abrash showed, it was badly out of sync for me when I watched the presentation, but you can see it here: http://www.youtube.com/watch?v=FefFfvriAwQ#t=64
And here's the side-by-side: http://www.youtube.com/watch?v=FefFfvriAwQ#t=149