No, none of the sites you mentioned solve the problem I posed.

Bigspeak, Keppler, Eagles Talent, and Celebrity are bureaus and function in a traditional way. Espeakers and SpeakerMatch are essentially speaker directories -- they make money from speaker's paying them a monthly fee or in a lead gen style.

Orate.me is new to me, I haven't seen it before. In a cursory look at their site, it looks like their speaker list is just NSA members.

Also the calendaring problem is easy to solve...

There's enough public data to develop a sentiment algorithm and solve the popularity problem.