LOS ANGELES (thefutoncritic.com) -- President Bush will address the nation on Thursday night regarding the American troop presence in Iraq. The planned 15-minute speech is scheduled to begin at 9:00/8:00c, forcing lineup changes in most of the country.

All four major broadcast networks are expected to carry the speech:

-- FOX will drop its previously announced new episode of "Don't Forget the Lyrics" at 9:00/8:00c in favor of a repeat of the show's premiere. Viewers in the Eastern and Central time zones will then join said installment in progress. In the Mountain and Pacific time zones, the speech will lead into a new "Are You Smarter Than a 5th Grader?" and the aforementioned repeat of "Lyrics."

-- NBC plans to shift the 9:00/8:00c repeat of "The Office" to 9:30/8:30c in place of "Scrubs" in the Eastern and Central time zones while Mountain and Pacific viewers will likely see both episodes.

-- CBS and ABC are expected to confirm their plans later today. It's not clear if they'll join previously scheduled repeats of "CSI" and "Grey's Anatomy" in progress or opt for a revised schedule in the affected areas.