I will point out my prior post.
Now I am sure that was a good theory but the rumors about the 50th special have given out a new option for his name, one most Whovians will know and remember and also key, it too is a part of the classic name of god, but has always been thought of as a different character. The rumor is John Hurt is called Omega in the 50th.
Now the significance here is :
Omega
He was one of 2, or three depending on source, Creators of Time lord Technology. Now in the books and comic books, it was three Rassilon, Omega, and the other. In the TV show the Other is never mentioned. In the Fiction the Other was the first incarnation of the Doctor. According to Time Lord tradition Rassilon founded Time lord Technology, made Regeneration Possible, and more or less was the God of Gallifrey in his own life. After he died his tomb was on Gallifrey and it was a massive structure with traps, and other things.
However Rassilon didn't actually invent it all, he had a Partner Omega, but when Omega created the Eye of harmony he was pulled in to it and sent to a negative universe. Twice he tried to return, twice he failed, foiled by the Doctor.
Now here is the problem, if John Hurt the Doctor goes by the Name Omega this will shatter current lore, but it would explain his not liking that name. Also it means at some point the Doctor will invent his own Tardis, and Rassilon will take credit, Also in the books and Comic Books the first living Tardis evolved from a Humanoid being. But thats a different discussion.
p.s. see
http://en.wikipedia.org/wiki/Nomina_sacra that will help with the Greek letters.
---------- Post added 2013-05-20 at 03:13 PM ----------
I should also point out One of the Names the GI said was the
Beast. This implies the Idea that at some future point the Doctor Becomes the Being locked up on the Impossible planet. The being that existed before Time. It is also understood that The Doctors evil will split away from him creating the Valeyard. So using the Idea of ΘΣ being the name of the Doctor, then it is highly possible the final series of the Doctor will have this split, but it also means the Doctor will end up 100% good. I could see him chasing his evil through time and space and finally locking it up on the impossible planet. Also the idea that the Doctor some how might be the source of the original Big bang. guess what He did that already. So technically he created the Universe, so technically he is God, in the Whoverse.