Teaser from Dr. Horrible’s Sing-Along Blog on Vimeo.

Seriously, I don’t think I’ve stopped humming or singing the songs from Dr. Horrible’s Sing-Along Blog.  So let me tell you, there’s a good reason it’s called a sing-along blog and that Joss Whedon and co. are working on a soundtrack.

But on to the more important parts, just who is this Dr. Horrible and how can I see what he’s up to with that freeze ray of his?  According to Joss’ himself, ” Dr. Horrible’s Sing-Along Blog is the (true) story of Dr. Horrible (wow, really?), a low-rent super-villain trying to get into the Evil League of Evil, defeat his boorish nemesis, Captain Hammer, and win the girl of his dreams, Penny (or at least talk to her.)”

Our low-rent super-villain, Dr. Horrible is played by Neil Patrick Harris.  The hero who keeps beating him up, Captain Hammer is none other than Nathan Fillion (who hasn’t done much comedy since Two Guys, a Girl and a Pizza Place back in 2001).  And the love interest, Penny, the cute girl from the laundromat he’s too shy to talk to, Felicia Day.

Currently, there are three acts, but at Comicon this past week, Joss let it slip that there will be a fourth act and a soundtrack still to come.  Your best bet is to purchase the series through iTunes (which secures any future episodes as well) for $5 or so.  Or, for this week, you can once again stream the episodes live over on Hulu.

For updates, be sure to follow along on Twitter.