Or at least include a transcript at the bottom so people can parse out the useful info without sitting through the video or trying to skip through and (likely) skipping right past the relevant nuggets.
I'm pretty sure most of the print media out there do exactly what you're doing - performing one or more interviews about particular topic. The good ones though take that material and turn it into an article that attempts to make a point using the information gained from the interviews as support.
There isn't anything wrong with what Mixergy is doing per se, it's just that there on the internet, I normally prefer the article format that can be skimmed first to determine my level of interest.
When something is written, you present the content and then ask for the readers time. With video, you demand the time and then present the content. Since my time - especially on the net - is precious, I'm rarely inclined to give it to you for free.
It takes a couple of days for the transcript to be up, but I always have one. (Unless the interviewee specifically asks me not to because he/she doesn't want what he says to be google-able.