Vatican News is reporting this morning that Pope Benedict will be known as 'Pope emeritus' or 'Pontiff emeritus' after his resignation February 28.He'll keep the name of 'His Holiness, Benedict XVI,' and will wear a white cassock without the cape called a 'mozzetta.'
Read the entire report on news.va.
Perhaps you've heard the name Pope Celestine V -- he was the last pope to voluntarily resign, at age 85, in 1294. NPR has a report about his history here.
You can read and listen to Pope Benedict's farewell Angelus on February 24 here.