Is Saddam's #2 Izzat al-Douri really dead or behind the bombings?

With today's carnage against a Shia holy place (a parked car exploded and killed 55 near Shiite Islam's holiest shrine located in Karbala), one has to ask who has the most anger and loathing of the Shia's. It was Saddam as we know, but Saddam's hatred against Shia's was carried out by Izzat Ibrahim al-Douri. According to BBC in an article in January of this year, they said the Baath party named al-Douri as its new leader shortly after the execution of Saddam. There have been many claims that al-Douri was killed a number of times. Has he been in hiding? Is it possible, that the once suspected underground bunkers, (that went so deep underground that when people visited these underground bunkers their ears popped) are still there? Al-Douri is capable of this action today. I know many think it is Al Qaeda and maybe it is. But just maybe, al-Douri is still alive too.