Ending months of speculation, Katie Couric marked her 15th anniversary on Today by announcing Wednesday morning that she is leaving NBC's morning news program. "I wanted to tell all of you out there that after listening to my heart and my gut, I've decided I'll be leaving at the end of May," she said on-air. "I really feel as if we've become friends through the years." Couric, the longest-serving anchor in Today history, is expected to fill the anchor chair at CBS Evening News, in a deal the Wall Street Journal says will also get her face time on 60 Minutes, her own documentary crew, and fetch her $15 million a year. "Sometimes change is a good thing," Couric told viewers. "Although it may be terrifying to get out of your comfort zone, it's also very exciting to start a new chapter in your life." As for Miss Perky's successor at Today, a source at The View tells the New York Daily News it's all but a done deal that Meredith Vieira will fill the vacancy.