ok, so i'll join the boat with the Danzo/Madara thing....
No, i don't think that Madara is Danzo but i do think that they're more than likely connected.
1. Danzo was around during the time of the Shodaime and Madara fight, it's unclear how old Danzo was at the time of the fight but what if, after the fight Danzo comes across Madara's "corpse" and takes one of his eyes?
- I know that the anatomy doesn't make sense. Both Danzo and Madara have the sharingan in their left eye, but can an eye be implanted on the opposite socket?
+This can explain why Danzo was so eager to destroy the Uchiha clan. He knows he posseses extreme power and it's said many times that only one with the sharingan can defeat another with the sharingan. Danzo was also killing 2 birds with one stone, destroying the Uchiha clan and getting rid of the most talented Uchiha.
+ Danzo is looking for Orochimaru's medical research. I think that like Kakashi, Danzo has a lot of draw backs while using the sharingan. Now that he's getting really old , wouldn't he need it more than ever?
-Also Danzo's character supports this, a ruthless militaristic man. Why would he waste his time with a normal Sharingan when he witnessed the power of the MS?
2. What has been stuck on my head for a while if the abilities of each eye. Zetsu said that Itachi's Tsukuyomi was in his left eye and amaterasu was in the right. Sasuke how ever is the opposite and i think Madara's is too. I think Madara used to have Amaterasu in his right eye. His left eye however contains the ability that Kakashi's (Obito's) sharingan has which is Kamui. I think that Madara has mastered "kamui" so well that he can maybe work it in reverse. Similar to Itachi's Tsukoyomi, where he mastered it so well that he was able to tourture for days. Notice how no one has mastered genjutsu as perfectly as Itachi. Thirdly, Sasuke. He has shown the ability to put out amaterasu, and now claims to want to experiment with it. Maybe sasuke will master amaterasu in a way no one else has. Finally, I think that the MS is a random collection of abilities that unlock depending on the person and are each given 2 abilities in each eye and depending on the combination, unlocking something new(Tsukoyomi + Amaterasu = Susano). We all know that japanese mythology is a huge influence in naruto. And maybe we've already been clued into something kinda obvious. Inari Not the weird little boy from the Zabuza arc. Inari is a collection of 3 to 5 japanese gods personified into one that has the power to control foxes. So far we've seen:
I think that we're missing 1 or more jutsu of the MS.
Finally, Danzo might have access to Amaterasu. I'm of course assuming that he has Madara's right eye, which i believe contains Amaterasu ( same as Sasuke) which i believe is also the reason why Madara is so interested in Sasuke.
All of this is based on speculation and i have no proof of any of it, nor did i claim i did. It's just what i got from the manga, opinions?