My company just began using WebEX polling during our webcasts and the results were quite interesting. The downside is that all of the information gathered had to be manually processed, which took time.
Integrating this information between WebEx-Marketo-SFDC via campaign progression statuses updates in Marketo Webcast Program would greatly enhance the efficiency of the process.
Full integration of every poll question would obviously not be feasible.
However, a common practice is to ask people if they'd like to be contacted at the end of a webcast. "Please contact me" and "Prefer Not to be Contacted" could be set up as additional progression statuses.