Dr. Horrible DVD: The Reviews are In
What's interesting is that director Joss Whedon decided to publish the DVD using CreateSpace, Amazon's DVD-or-download-on-demand division.
Also interesting to check out how the Dr. Horrible fan community is evolving on the official site.
From NewTeeVee's assessment of the DVD:
As for special features, the centerpiece of the DVD is definitely Commentary! The Musical, a full-length commentary track that is a completely original musical in its own right. Redefining post-modernism (”I think you just broke the ninth wall” is a remark made towards the end), Commentary! is actually a fun, behind-the-scenes glimpse of the production, heavily laced with inside jokes set to music very nearly as good as that in the actual production. There is an entire ballad about the video game Ninja Ropes, which they all played on their iPhones while on set (Nathan Fillion holds the high score), and co-writer/Groupie No. 2 Maurissa Tancharoen sings a song about how she didn’t get cast as Penny because “no one’s Asian in the movies.”
Here are some earlier pieces where I've written about the significance of the Dr. Horrible experiment.