A few things: You position your app as a "collaborative editor", yet it took me almost two and a half minutes on the videocast to even get a look at it. I know you want to show how easy it is to sign up, but is that really necessary? You're not selling a sign-up/sign-in page, you're selling your service. Furthermore, if I were selling an app that does collaborative editing, I wouldn't harp on on the whole "revision control system" angle. It's redundant knowledge - I know it's there by seeing the amount of dates & times (and it's also briefly shown in the videocast), so I'll use it when I need it. See how Wikipedia does it: They don't go on and on about how each page has a "History". All that they do is put an "edit" button on each page or page section. Less in your face == much happier users.
Next, when I read the description, I was thinking of something like MS Word, online, with multiple people working on the same document, yet it comes across as an ajax-ified blog engine: "Version 1 by Nick today at nn:nn pm" isnt really information I need staring back at me at all times.
Some nit-picks: I would edit out the breathing-into-the-mic. No offense, but it's kinda grating :) And Charlie sounds kinda bored/indifferent...