It seems that there has been some confusion on the "official" title for the upcoming God of War II. Hoping to clear up this confusion, Sony released a statement on the matter, and yep, it clears it up just fine.

"…there may be some confusion out there regarding the actual name of the title, so we wanted to clear that up… There have been some reports of some sort of "Divine Retribution"… However, please note the official name of the title is God of War II."

So there you have it, the ultra-official name is indeed God of War II.