Dr. Horrible's Sing-Along Blog DVDCross one item off your holiday shopping list. At $15 this one is such a no-brainer, you can send us one too.

Dr. Horrible’s Sing-Along Blog, this summer’s runaway sitebuster from creator Joss Whedon is finally available on DVD just in time for the holidays. The special edition DVD ships December 19th though you can pre-order now with 2-day shipping to ensure you actually get one in time. Pre-order sales are already shooting up the Amazon charts.

Arguably the most popular original online series to date, Dr. Horrible gave the nascent web series community a certified commercial success and a reference point of what an online hit actually looks like. Even before the show’s soundtrack dominated the music charts in September, the series had already grossed over $2 Million by most accounts just from iTunes downloads in the first few weeks of its release.

The DVD is loaded with special features as expected: making-of featurette, Evil League of Evil (ELE) applications and musical commentary from Joss and his co-writers (his brothers Jed and Zack Whedon and Maurissa Tancharoen) and of course the stars—Felicia Day, Neil Patrick Harris, Simon Helberg and Nathan Fillion. Yes, you read that correctly, even the commentary is a muscial. “Commentary! The Musical” is the most painstaking and exhausting piece of whimsey I have ever mistaken for a good idea,” wrote Joss today on Whedonesque.“It has nearly twice as much music as Dr. Horrible itself — since you can’t really talk that much during a commentary musical or it sounds like a regular commentary.

As Joss admits , the ship date is a little close for comfort for Christmas shoppers:

The listed street date is, by the way, a little later than we’d expected — I’m hoping Amazon is just playing it safe and we can beat that date. More on that as we learn it. Expect a twittering sensation.

With confirmed talks of a sequel in the works, it’s time to start thinking about what’s next from the internet’s man with the Midas touch. And there’s no shortage of places teeming with speculation. Joss has made it pretty clear he wasn’t just flirting with this new medium:

Joss WhedonAll that rhetoric about the future of entertainment that flew about during the Strike is still entirely true. We need to find our own way of producing entertainment. A lot of people are watching Dr. Horrible to see if it’s any kind of model — way more people than I expected — and it means everything to me to help pave the way for artists to start working and making a living from the ground up. There are a couple of real pioneers in this that I know personally: Felicia Day, I’m thrilled to say, and choreographer Chris Elam are both looking far ahead in terms of monetization and interactivity.