KazeKage1: "What if... Kagami Uchiha was Tobi!!
I'm starting to wonder if the fellow pupil of Hiruzen Sarutobi and Danzo Shimura, Kagami Uchiha (seen in the last thoughts of Danzo, after his battle with Sasuke) could be Tobi (Madara Uchiha)? Since i doubt very strongly that Tobi is actually Madara! I have found a couple of pages from the manga which support my theory:

In the following page, the Tsuchikage makes reference to Madara's ''Mooneye Operation'' to be alot like what Danzo's idea of the Shinobi World is... i believe that Madara and Danzo think alike for their respective plans because they were fellow pupils, and Kagami seemed to be in Danzo's three-man cell rather than Sarutobi's... which explains why they think alike!
http://www.mangafox.com/manga/naruto/v50/c467/17.html

Here, we see the three-man cells of both Sarutobi and Danzo. As I said up above, i believe Kagami Uchiha and Akimichi Torifu were in Danzo's squad, under the 2nd Hokage, like Sarutobi's squad.
http://www.mangafox.com/manga/naruto/v51/c481/

I found this other page while re-reading the fight between Madara and Minato during Naruto's birth and the Kyubi attack of 16 years ago. After their ''Battle of Speed'', Minato describes Madara's space-time ninjutsu to be better than his own space-time ninjutsu and even the 2nd Hokage's, Nidaime Hokage. And it might just be me forgeting stuff, but wasn't that the first and only time someone spoke of the Nidaime Hokage to have had space-time ninjutsu?? And if he did, then it explains that he could have tought one of his students the space-time ninjutsu techniques! Furthermore, Masashi Kishimoto seems to like making the students become stronger than their master in this series (Orochimaru and Sarutobi, Sasuke and Kakashi, Naruto and Jiraiya, Shikamaru and Asuma...) so it makes sense that the student of the 2nd Hokage could have developped space-time ninjutsus even better than his master.
http://www.mangafox.com/manga/naruto/v53/c502/11.html

I have no page to support my following argument, but it makes sense anwyays, you'll see!
Kishimoto told on many sites that the name of the 2nd Hokage (Nidaime) was Tobirama Senju... and alot of people, including me, think that the name Madara Uchiha used, ''Tobi'', could have been in reference to Tobirama Senju, the 2nd Hokage. Now, I think this is very probable because if Kagami Uchiha studied under him, than it is indeed a strong possibility that he would've taken a nickname from his old master. Tobi from Tobirama.

To add to my theory about Tobi / Kagami Uchiha, would'nt it be great if the reason why Tobi seemed so surprise to see Kabuto's last Edo Tensei coffin was because it's Madara Uchiha?! And that Kagami Uchiha could be Izuna Uchiha's (Madara's little brother) son!? Maybe he was Madara's nephew and after his father's death he was raised under Madara's ideologies? This makes sense since Madara and Izuna are the same age as Hashirama and Tobirama, so Kagami could have easily been the child of either of those Uchiha brothers! And it could make for a very interesting plot twist in the Naruto series!"

Remember,this is just a thought

tayoccu:

Dude its in the manga

codeaddict: Just finished reading 591. Madara is definitely not going anywhere!

firestar:
I just realized something...
Madara, where is his better half? Fighting one who have found closure(Tsunade-Dan) is pretty dangerous...

eyoniggar: The whole thing is just twisted, fine hiruzen claimed he stopped the 3rd casket, how come Kabuto was explaining to Tobi that a soul sealed within the death ripper god cannot be summoned, of which was the reason Oro couldnt summon Yondaime Hokage during that very battle. Was it that Hiruzen wasnt the 1 that stopped the casket? or what is that Kabuto is just yarning opata?

KazeKage1:
If Kabuto/Tobi finds out that Madara broke free fromthe ET..things could get a little ugly.
Eyo,
I'm with you on this one. For those insisting why Hiruzen didn't stop the 1st two summonings,you can send fan-mails to Kishi.#Joke
Sarutobi stood a chance against both hokages but knowing the 4th's exploits,he panicked&STOPPED the 3rdcoffin from opening cause if he didn't,he wouldn't last in battle.

rapmike:
i dont believe that because the fact thathe made some hand signs and thought that he stopped the third coffin does not mean he stopped it...kabuto said that oro failed to resurrect the 4th because his soul was sealed AND NOT BECAUSE SARUTOBI STOPPED HIM.BESIDES I STILL ASKED THE QUESTION, IF HIM IS STOPPED THE THIRD COFFIN WHY DID HE NOT STOPPED THE FIRST TWO? AT LEAST HASHIRAMA AND TOBIRAMA ARE NOT EASY TO BEAT ESPECIALLY AS HE IS CLOSE TO THEM.

tayoccu:

On why sarutobi didn't stop the first 2 coffins? Read the first manga page I posted.
On what kabuto said, on more than 1 occasion we've seen characters in narutoverse make claims based on their own perception of the truth.[i][/i]
If kabuto's theory were true the coffin would probably have come out, but oro would have been unable to animate the corpse.

firestar: Tsunade has been motivated, what I want to see is a new jutsu barred from copyright law.

And Sassy-ike should infrared the mighty dragon sennin to do something useful before 'im head korrect.

texazzpete:

Why do you folks expect anything different from her?
she is NOT on Madara's level. All the Kage combined are still not on his level. End of story.

KazeKage1: @TAYOCCU
I remember someone saying thing a while back but was shouted down. Kagami was notably absent(as most Uchihas) when Tobi used the kyuubi to attack Konoha. He does look like the adult version of Tobi but the question is: Was he worked on? (Based on the Zetsu theory), does he have the same jutsus Tobi uses?
#iInvestigate

KazeKage1: Any idea what could be in those scrolls Jugo found?

panaroma: I have a feeling Sasuke and Kabuto will become partners...

texazzpete:

Why do you folks expect anything different from her?
she is NOT on Madara's level. All the Kage combined are still not on his level. End of story?

...Tory
Story continues jare...
Edo-Tensei cheats. Its useless to battle a puppet without tracing he that owns the ropes neh?
Now that Madara has become "mortal"...
That probably means more Susano'o _ba_sh_in_g

Who knows what sort of power Dan imbued the Slug Princess...

tayoccu: On the issue of kabuto and sasuke partnering, it won't happen, remember the condition required for him to escape the izanami? Dats why.

firestar:

...Tory
Story continues jare...
Edo-Tensei cheats. Its useless to battle a puppet without tracing he that owns the ropes neh?
Now that Madara has become "mortal"...
That probably means more Susano'o _ba_sh_in_g

Who knows what sort of power Dan imbued the Slug Princess...

Twisting:
it'z vewi simple turn good,then bad.

rapmike: Now that we know that MADARA IS mortal, wonder what kishi will show next...
i hope he shows naruto vs tobi no name no body or better still
show where sasuke will go to