I think its more then just the Baathist people. Terrorists brainwashed by Militant Islam are all flocking to Iraq with the prospect of murdering Americans and other non-Muslims. Many of them could care about Saddam or his former regime. All they want to do is target non-Muslims and galvanize the population to do the same. They are aided by mosques, media, schools, etc. who are in those states around Iraq.
I think its more then just the Baathist people. Terrorists brainwashed by Militant Islam are all flocking to Iraq with the prospect of murdering Americans and other non-Muslims. In Fallujah, it's predominantly the Baathists. In Najah, it is the religious fanatics you mention.
In Najaf, the goal will be to eliminate Muqtada al-Sadr.
Elsewhere, it would help if Pakistan and Saudia Arabia target their own radical Mullahs as they are obviously a threat to the current regimes and as well as a threat to us. In Gaza, the IDF has ben handling the problem quite well lately.