WOW, Ralph Fiennes already had me excited, but Sophie Okonedo is a simply inspired choice. What a positively dynamite pair. Simon Godwin is directing as well - I loved his Twelfth Night, and wish I could have seen his Measure for Measure. I desperately wish I were in London when this is happening, and I eagerly await the (hopefully) upcoming NT Live Broadcast.
I think Antony and Cleopatra is probably Shakespeare's most under-valued play. It is every bit of the quality of Macbeth and King Lear but often gets sidelined as a second-tier Shakespeare. The only problem is that it's enormously difficult to cut more than a hundred or so lines from the play and have it maintain coherency. Regardless, I would be eager to see Okonedo take on one of the great roles of the stage.