Quote Originally Posted by 'X-Ifist',index.php?page=Thread&postID=190506#post190 506
Thinking of
DK Tank 12%spell dmg
Bomkin druid 5% crit 13% increase spell dmg
Demon lock 10% spell dmg
Elemental shammy 3%crit hit 280 spell dmg 5%haste
Healing priest

can annyone tell if all this will stack?
No, the DK, druid, and lock debuffs don't stack. You can see which abilities stack here:
http://www.mmo-champion.com/index.php?topic=14214.0