"Do the Iraqis celebrate TET as they do in Vietnam?"
They probably celebrate every single American casualty in Iraq. Similar to the Vietnamese who fought the Americans in any way the could, and tried every trick in the book to flee their country when it was over, so will the Iraqis ulimately reap what they are sowing as we speak. They seem not to have learnt much from their Iranian neighbours, who toppled their Shah in favour of the 'grand-inquisiteur' of their own choice, Ayatolla Khomeini, only to find out too late what they had bargained for.