Taping was from a distance so the audio, at times, is weak. Listening with ear buds suggested. Also, a non-audio version of the complete set of PPT slides is available for more reflective viewing via my SlideShare account.
Below is a snippet of a part of the larger video that explains the key concepts and PPT-based animations that are used in the Keynote presentation.
Finally, if you are unfamiliar with the IM technology, you might want to watch the following brief introductory video before viewing the Keynote video. The video is a bit dated with regard to current understanding of how IM may work, as explained in the Keynote video above. However, it is a good video for understanding the task demands of IM