Whoever you pick to beat Wladimir has to be big, fast, have a powerful jab, a fair punch and plenty of experience. Lewis, Foreman, Ali and Holmes come to mind. In their prime and on a good day they could get the job done. Look around, do you see anyone like that? One thing I forgot, they need a good chin too.
Big, fast, powerful jab, decent power, plenty of experience and a good chin.