Here's what it says on the RSC website:
"The RSC returns to London with Gregory Doran’s production of Shakespeare’s comic tale Twelfth Night, transferring to the Duke of York’s Theatre following its run in Stratford-upon-Avon.
Award-winning actor Richard Wilson makes his RSC debut as Malvolio. Joining Richard will be James Fleet as Sir Andrew Aguecheek and many familiar RSC actors including Sam Alexander (Sebastian), Nancy Carroll (Viola), Alexandra Gilbreath (Olivia), Jo Stone-Fewings (Orsino), Miltos Yerolemou (Feste) and Associate Artist Richard McCabe returning to the Company following his acclaimed performance as King John."
It should be good! Twelfth Night is one my favourites..