I finally got the official word on this from a guy over at beartooth bullets.
We're pleased to report that provision was included in the Defense Authorization Act of 2008, signed by President Bush in January. Here is the language, taken directly from the Act:
SEC. 594. CONDUCT BY MEMBERS OF THE ARMED FORCES AND VETERANS OUT OF UNIFORM DURING HOISTING, LOWERING, OR PASSING OF UNITED STATES FLAG.
Section 9 of title 4, United States Code, is amended by striking 'all persons present' and all that follows through the end of the section and inserting the following: 'all persons present in uniform should render the military salute. Members of the Armed Forces and veterans who are present but not in uniform may render the military salute. All other persons present should face the flag and stand at attention with their right hand over the heart, or if applicable, remove their headdress with their right hand and hold it at the left shoulder, the hand being over the heart. Citizens of other countries present should stand at attention. All such conduct toward the flag in a moving column should be rendered at the moment the flag passes.'