Emma Watson arrived at today's London premiere of Harry Potter and the Deathly Hallows Part 2 in a stunning floor-length Oscar de la Renta gown. It's the eighth and final installment in the series, and the entire cast turned out to bid farewell to fans, many of whom have been camped out for days in Trafalgar Square just to get a glimpse of Emma and her costars Daniel Radcliffe, Rupert Grint, and Tom Felton. It's a big week for Emma with the film opening in the UK today. She's heading back to the States next week for Monday night's NYC premiere where we'll be streaming LIVE from the red carpet. The fun doesn't stop there for the cast with Emma expected to sit down with David Letterman on The Late Show Monday and Live With Regis and Kelly on Tuesday. Stay tuned for more coverage from the world premiere of Harry Potter!