Everyone who works with a retirement plan should act in a fiduciary manner, but many have claimed over time that they are not fiduciaries. Why? They don't want the obligations, they don't want the responsibilities, they don't want the liability.
Until recently, it was fairly easy for outsiders (3rd party providers) to stay outside of the definition of fiduciary under ERISA, but DOL proposed regulations issued on October 21 will pull many under the umbrella of the fiduciary label.
Are you one of the "new fiduciaries" who didn't know you were? http://www.aon.com/attachments/fiduciary_redef_nov2010.pdf