*raises hand* David Tennant is right, his name is "The Doctor", but it's not wrong to call him "Doctor Who". Doctors One through Nine are called "DOCTOR WHO" in the credits! In fact, other former Doctors refer to him as "Doctor Who".
David Tennant - perfectly expresses the impossibility of trying to explain Doctor Who - can't explain it, just watch it! Also, I am still thoroughly sad that David Tennant was not allowed to use his Scottish accent while playing the doctor.