The Doctor's Name.
Don't get me wrong, but I think this can lead to one of three or four possibilities:
a) They reveal the name. Fans everywhere revolt as the main premise of the show is spoiled.
b) They reveal the name. It makes perfect sense. Fans everywhere are happy.
c) They don't reveal the name. Fans everywhere revolt about the false hype.
d) They don't reveal the name. Fans everywhere are satisfied.
Regardless of which occurs, I'll probably end up watching. But mainly, this made me think about something more specific - what happens when you make a long-running premise? What if you change things? Look at Harry Potter, The Song of Ice and Fire and (shameless self-promotion) Zendir. The characters have actual personalities. The characters will do actual things and any alterations to the main plot will be profoundly evident to the reader, not just the characters.
Why do I want to do this? Good question. I have no idea.
I probably just enjoy writing and creating believable worlds.