I didn't post a link to it because I see links to it everywhere, and you've already seen it anyway, because you're a cool person who is perpetually in the know. Even so, I couldn't take the chance, because the one thing most links to Dr. Horrible don't include is a dire warning about its ephemeral nature.
That's correct: it will be dragged off the Internet very soon, to be placed on a DVD and made available for purchase. Parts one and two are already avaiable at the site, and part three comes out on Saturday. After that, it all gets pulled down on Sunday. It's a supervillain musical written by Joss Whedon, starring a bunch of awesome motherfuckers.
Why are you still here.