he is not obito uchiha he is madara uchiha which he states in the manga as you see a glow in his right eye ( our left) the sharingan, this happens after deidara was killed and a little after you meet konan
But, Then again Tobi may be Obito. Because he has his Left sharingan eye(though we do not know if he has his right one)and he has bolts all over his body. Kakashi took Obito's Right Sharingan Eye and Obito was crushed. We only see Tobi's left eye, so there is a chance Kakashi has his Right one.
I don't think this matters or anything but Obito is Pig Latin for Tobi...
Hey go to http://www.youtube.com/watch?v=OjJtceW-16s this is a video i made it will give you more info in the video and the comments, you must read some of the comments and watch the video... more then just the sharingan.
yup thats him and tobi takes off half of his mask to sasuke and goes on fire because itzchi gave sasuke his eyes somthing like that its in Chapter 397-402 then tobi/ madara shows kisame his face in Chapter404