I agree with Brian. It took me a bit to get into it, but that could be the fault of the kids who were (please contain your shock and suprize) fighting and I couldn't hear all that well. I only really missed being able to pay full attention to the first five minutes, so...
Can I just say that you sound quite a bit like DJ Grothe of Point of Inquiry? I can't? Oh...ok then.
I'll definately bee keeping this one subscribed. You have managed to have interesting topics, they're long enough to be in depth, but short enough to keep my interest (and not take too long to download). You don't have any irritating vocal habits (for example, take a listen to Evolution101, which I really like, but Dr. Zach does that teeth sucking thing as a gutteral stop...AHHHH!!!) to make me want to reach through my computer and kill you. Serious enough to be taken seriously, but humorous enough to not seem snobby.
I give it an A.