From USSF (July 23, 2003)

In the recent Confederations Cup, there were several occasions when a player removed his jersey following a goal by his team. Subsequently, news reports have appeared indicating that FIFA may issue an instruction that such an action be treated as misconduct.

This has not occurred as yet and, until such time as USSF receives new information, all referees must continue to adhere to the following guidance provided in Memorandum 2002:

Referees are reminded that they must take action against goal celebrations that incite, are provocative, or take an excessive amount of time.

Simply removing the jersey in a momentary emotional reaction to scoring a goal should not be treated as misconduct unless doing so excessively delays the restart of play or is performed in such a manner that, in the opinion of the referee, it taunts, provokes, or incites opponents.

U.S. Soccer will quickly bring to your attention any change in this approach if and when it is announced officially by FIFA to the national associations.