One of my favorite blogs "It's All Virtual" (hosted by Dennis Shiao) has posted a predictions for 2010 in Virtual Events. It's definitely worth the read.
2010 Predictions For Virtual Events
"Virtual events have incorporated a lot of on-demand and live video – however, to date, the majority of attendee interaction has been via text (e.g. private text chat, group text chat, etc.). Many platforms have enabled the use of attendee webcams (a la Skype) and that was a nice start. In 2010, I believe that the virtual event platforms will integrate with third party video conferencing technologies in a big way – stirred largely by client demand for it." Full article is HERE
Plus, make sure to check out 2009 Virtual Events : Year in Review