I use "peshmerga" in the long-standing sense of armed Kurdish fighters, whose loyalty is to their ethnic group.

Some are in the uniforms of the Iraq national army; their true loyalty has been the subject of many articles over the past few years. A few quotes follow; more can easily be found on Google.

Perhaps the most famous: "Keeping Iraq Intact", CBS/AP (December 28, 2005)
http://www.cbsnews.com/stories/2005/...n1166972.shtml
The soldiers said that while they wore Iraqi army uniforms they still considered themselves members of the Peshmerga - the Kurdish militia - and were awaiting orders from Kurdish leaders to break ranks. Many said they wouldn't hesitate to kill their Iraqi army comrades, especially Arabs, if a fight for an independent Kurdistan erupted.

…Afandi said his group had sent at least 10,000 Peshmerga to the Iraqi army in northern Iraq, a figure substantiated in interviews with officers in two Iraqi army divisions in the region.

"All of them belong to the central government, but inside they are Kurds ... all Peshmerga are under the orders of our leadership," Afandi said.
BBC (March 11, 2005)
Entering and leaving the area where the PKK camp is located is like crossing a border. The peshmerga of the Patriotic Union of Kurdistan, dressed now in their Iraqi National Guard uniforms, check all the cars coming in and out. There is even a customs official.
From The Scotsman (November 5, 2006)
Hamid Effendi, KDP minister for the peshmerga, has said, "The Arabs in southern Iraq struggle to build a new Iraqi army, but the Kurds already have one. The peshmerga wear Iraqi army uniforms, but they are still Kurds. We have about 60,000 peshmerga. And now they've got big guns"
This discussion is relevant today as Kurhish units of the Iraq national forces move to Baghdad as part of the surge. Much in the news; here is a balanced look:
Voice of America (Feb 16, 2007) "Iraqi Army Soldiers From the Kurdish North Head to Baghdad"
http://www.voanews.com/english/2007-02-16-voa27.cfm

Adding to the confusion;: many news accounts note that the peshmerga often do not wear uniforms.
New York Times (Feb 23, 2007)
http://www.nytimes.com/2005/02/27/in...&ex=1174276800

The pesh merga are everywhere in Iraqi Kurdistan - along the highways, atop government buildings, riding in convoys. They wear a hodgepodge of uniforms, from traditional baggy outfits to desert camouflage hand-me-downs from the United States Army. There is one thing that appears to be consistent, though: they think of themselves as Kurds first and Iraqis second.