The veteran rockers make a 'surprise' appearance at Texas festival<br />
Singer is taken to hospital moments before Stockholm show
Drummer says he just wanted to 'try it'
Fans who own 'Death Magnetic' can enter the competition
'The Complete Metallica' is due out this spring
Bands set to headline Sonisphere this summer
The game also features Foo Fighters, Queen and Slayer
Guitarist Jeff Beck also makes the list of 2009 honourees
Rockers confirm rumours on website
Band set to go for Internet-only approach