[Cael]

I'm going to go out on a limb here and say Tobi is NOT Obito. Rather Tobi is Obito's father... *cue Darth Vader mask breathing noise*

Spoiler for Size - A few reasons why:

-His obsession for peace stems from the loss of his son (Obito) to war
-He's from the Uchiha clan and was a part of Konoha, which explains his vast knowledge
-He would be a little older than the 4th Hokage
-He had a hand in arranging the Uchiha clan to be in a meeting during the 9-tails attack
-He tried (not wholeheartedly) to kill Naruto as payback to the 4th for not protecting Obito
-Obito's hair, his mask/goggles affinity and his MS techniques are similar to Tobi's because they are kin
-Their names fit into the father-child naming scheme