Metallica To Release Death Magnetic Album As DLC For GH III, IV

I have to admit that my love for Metallica has been waning over the past several years. Not only has their music not been as great, but ever since they started promoting the suing of fans for downloading music, I've just not been as excited by their music. One place that I still enjoy hearing it is in both Guitar Hero and Rock Band.  Well it looks like I might actually purchase their latest album, this time for Guitar Hero, marking the first time I've cared to obtain an entire Metallica album in a decade or so.

Their latest full studio release will debut on Guitar Hero III: Legends of Rock at the same time it is available for purchase in stores. I'll be interested to see how it sells in-game as opposed to traditional downloads via iTunes and such. Motley Crue had great success with releasing a single in Rock Band at the same time it became available on iTunes.

What is really interesting is that the album will also be available as DLC for Guitar Hero IV, which raises a few questions. If I buy this DLC for GH III, will I still need to purchase it again for IV? If not, then does this mean other DLC will transfer as well? If not, I think I'll hold off on downloading this for a while.