Though Pierce Brosnan is constantly saying that he wants to take a slightly longer break after his work on The World is Not Enough, producer Barbara Broccoli is still moving forward on plans for Bond 20. According to the Mr. Showbiz website, Broccoli is in negotiations with British actor Nigel Havers (Chariots of Fire, Empire of the Sun) to take on the next film’s villainous role. The site quotes the actor from Matthew Wright’s London Daily Mirror column, saying, "I've always wanted to play a Bond baddie. It would certainly be playing against type."
Personally I wouldn't bank on this rumour turning out to be true as it’s still very early days. You must remember that Anthony Hopkins was originally rumoured to play Alec Trevelyan in Goldeneye and that never happened.