Some have doubted the authenticity of the papal coat of arms that was released by the diocese of Munich and Freising earlier this week, wondering why, if it was the true coat of arms, the Vatican hadn't released it instead. Well, earlier today, L'Osservatore Romano, the official newspaper of the Vatican City, published an article "Lo Stemma di Papa Benedetto XVI" with a graphic of the same coat of arms released by Ratzinger's former Bavarian diocese:
È tradizione, da almeno otto secoli, che i Papi abbiano un proprio stemma personale. Anche il Cardinale Joseph Ratzinger, eletto Papa ed assumendo il nome di Benedetto XVI, ha scelto uno stemma ricco di simbolismi e di significati, per affidare alla storia la sua personalità ed il suo Pontificato.
I would post a link to that article here, but unfortunately since I found it, the newspaper has updated its site with the April 29 edition and it appears that they do not make available old stories in an accessible archive. A higher quality color image of Pope Benedict XVI's coat of arms is available from the Wikipedia here.