UPDATE: Oprah has just made another announcement. Christina Aguilera will join Oprah for a show that will be taped at 10 a.m. at Radio City Music Hall in New York on May 7 to air at 4 p.m. that day. Xtina will perform and talk to Oprah. Other special guests are expected to make appearances during the broadcast. To get tickets to the show go to Oprah.com.