TAYLOR SWIFT is the best-selling digital artist of all time, and a four-time Grammy winner -- and she's always been Ellen's pal! The country music superstar is stopping by to celebrate the release of her brand new album, "Speak Now." She'll also perform a new single, and one of her well-known hits!Ellen is still working hard to find DJ Tony a date, and today she's putting some of the prospective ladies to the test... on the Know or Go machine!