UPDATE: Joss Whedon wrote a short intro for Dr. Horrible. It's up at the Hulu blog. Meeting Joss and now having him use Hulu in a sentence caused me to wet myself. Since those events occurred on two different occasions, that's two pairs of pants I've ruined.
Just launched to Hulu: Joss Whedon's musical tragicomedy, Dr. Horrible's Sing-Along Blog, starring Neil Patrick Harris and Nathan Fillion.
Joss and his brother Jed wrote all the music, and it's good, which won't be surprising to Whedon fans familiar with the Buffy The Vampire Slayer episode "Once More, With Feeling".
Here's one of the musical numbers, "Freeze Ray", one of my favorites from the, what should we call it, web original musical? Weborigical?
Here are all three acts of Dr. Horrible, tied together into one video.