After reading about 20 pages of comments, predictions, and down right fanboyism every time a manga discussion page is created, I feel the need to express my own opinion just this once and agree/disagree with some of the people on here.
Here goes... 1) I don't think a talented writer like Kishimoto would make Tobi's name/identity be as obvious and simple as an anagram for Obito. He's surprised us (his readers/fans) time and time again with Naruto characters' past, identities, and historical information, so it makes no sense for a man who's planned a complex, multi-generational story arc just to make Tobi's identity so predictable that a 7 year old can figure it out. I agree with some people here that Kishimoto is deliberately luring fans to think that Tobi is Obito, so he can have the last laugh when he reveals Tobi's true identity. Whatever his name comes out to be, I believe what comes after, is a little background on what his motives/reasons are (whatever they may really be) for plunging the world into war.
2) As far as Tobi being Obito goes, how is it that a boy who can't even keep up, let alone surpass Kakashi, be able to go toe to toe with the 4th Hokage (his sensei), become resurrected for an unknown reason, be two different ages at the time Tobi and Minato duel, and supposedly have a change of heart, personality, voice inflection and tone, and effectiveness in battle? I won't debunk predictions that Tobi could be Obito's dad, Izuna, or some other Uchiha, because the way the plot is going, Tobi could be anyone, except Obito, at this point. Tobi being past or future Obito is highly improbable in my opinion. Anyone else who still think Tobi has got to be Obito is being fooled by Kishimoto.
Anyways, that's my opinion and anyone can agree or disagree with it. I'm one of those readers that stick to the facts that Kishimoto have given us. No more, no less. Cheers.