Out goes Tucker Carlson, in comes NBC News veteran David Gregory. From Washington, the White House correspondent will begin filling the 6pm slot while continuing to carry on his regular duties, which includes playing fill-in for Matt Lauer on Today. Gregory's show will be called Race for the White House, which, by definition, has a sell-by date of November. Meanwhile, the adept Andrea Mitchell will begin anchoring the 1pm dayside news broadcast, a similar role she had leading up to the 2000 election. [TVN, AP]