Overview: Comedian TINA FEY, creator of the new comedy "<i><b>30 Rock</b> (NBC, Wednesday @ 8pm)</i>," gets a firsthand lesson on how to be a host from the queen of talk shows herself, ELLEN. Will Tina make the cut as Ellen's stand-in? "<i><b>Grey's Anatomy</b> (ABC, Thursday @ 9pm)</i>" star KATHERINE HEIGL talks about her romantic engagement to her musician boyfriend. And, can Ellen get to the truth about the rumors of on-set drama on "Grey's"? CORINNE BAILEY RAE performs "<u>Put Your Records On</u>" from her self-titled debut CD (<i>in stories June 20, 2006</i>). Kyle Paxman, known as the "JILTED BRIDE," who discovered her fiancé was being unfaithful six weeks before her wedding, shares her inspiring story of how she turned heartbreak into an amazing accomplishment.