Activision reveal a new installment in the Guitar Hero series, this time based on Metallica.

We've known that Metallica have been lined up to follow in the footsteps of Aerosmith in getting their own band-exclusive version of Guitar Hero for a while now, but Activision have just made it official.

Here's the launch trailer for Guitar Hero: Metallica - it's not much, even as far as teasers go, but we can expect to see more once Guitar Hero World Tour is out of the door.

Guitar Hero: Metallica is slated for a Q1 2009 release.