The Fourteenth Doctor has been cast

[classicdrogn]

Indeed, how the Doctor looks, and in the details (dress sense, quippy vs. serious, whether or not they like pears) even how they act is unimportant, compared to maintaining the core elements of the character. Technological genius less obviously matched by a keen social perception, inability to leave an innocent to suffer, injustice to fester, or a mystery unsolved, eschewing violence whenever possible and applying it with resolute efficiency when unavoidable. Add a TARDIS control room set and a few key props (the TARDIS exterior and some form of sonic screwdriver, mainly) and you can drop the actors onto whatever location or sound stage set with whatever supporting cast you like and tell a good Dr. Who story. Lose more than one or two, and it doesn't matter if there's a police box and a handheld bzzzt! and the technobabble is correct and the antagonist of the week is as iconic as Daleks or Cybermen or whatever, it's just not going to be The Doctor.