Whatever began with a Vocaloid-Song evolved to one of the biggest Anime hypes of the last few years. Who couldn't enjoy the action filled black rock shooter trailer which was released a few months ago?
Finally the full OVA is released with a DVD as a free addition to some magazines sold in Japan. The subtitles added are in 5 languages, including German and English. Basically they want to make money by merchandising, just like Lucas did with Star Wars.
But is the final OVA really as good as the trailer? No. And that's very sad. Black Rock Shooter is a nice slice of life anime with a parallel plot in an alternate worldv but the main story kind of got lost in it. If it wasn't for the hype you'd probably forget it very quickly after watching.
I'm not trying to say that it is bad, but it isn't far as good as expected. Let's just call it a victim of it's own hype. ;)