Here's one more reason why video conferencing will dominate business communications.
Video delivers a high quality, totally committed communications experiences. The old methods of poor quality audio (pops, whistles, artifacts, garbled phrases) prevent people from concentrating on the communication. In long and boring audio conferences people check their email, or play solitaire and are often surprised when they are asked something, requesting that the question be repeated. Ughhh. What a waste!
We live and work in an attention deficit world. Only when we are totally involved in the collaboration at hand will the real productivity occur. That can only happen when at least the visual, aural and audio senses are engaged. Distractions are not so easy when others are watching you, and you know they are.