Publicare just announced an update to their comparison study of web conferencing solutions. The comparison site is www.webconferencing-test.com. I have written about the site before... At first in a disparaging manner, as I thought they were merely promoting a sponsored solution. But I changed my tune and now recommend that people doing an initial survey of web conferencing solutions spend time perusing the site. If nothing else, it helps you to organize your priorities and selection criteria so you can decide what is most important for you in making a decision.
Of course we all know the danger of simply looking at a rankings site and taking the summary information as the entire story. Even Siskel and Ebert came to loathe how "Thumbs Up" and "Thumbs Down" came to replace their longer, more complete film criticism and reviews in many readers' minds. But Publicare lets you drill down to the underlying test criteria it uses in coming up with the final scores and also includes some overview information on each product.
The comparison now features 21 products, mostly concentrating on the use of web conferencing for collaborative group meetings (typically in a small business or personal context) rather than larger public events in more of a broadcast mode. They have a smaller section that looks at enterprise solutions, but even here the focus is on collaboration rather than presentation, evidenced by the fact that they review WebEx Meeting Center rather than Event Center. So use the information in the proper context and you should get good value from their organized approach.
By the way, the site naturally leaves out plenty of competing alternate solutions. It's awfully hard to stay abreast of every conferencing solution on the market. Vendors are updating and introducing web conferencing products at a bewildering pace. That's why I try to stay focused on large event applications. It helps me stay sane!