Well, I think that the next element should be Earth but no one really knows. What blood line abilites? Naruto so far doesn't have any. LOL
Does anyone else think that naruto will learn his fathers other abillities? I do. Teleport and such.
Naruto's mom will show up again...but don't think that she is the mizukage. She should be around 35 years old (21 years at the time of narutos birth) so she can be almost anyone. Mizukage can be the naruto's sister for example. . .
Tobi IS Madara's current form on Earth. I think that the Madara/Tobi that we see isn't a real one but a projection of a former self. And he needs the power of the 9 beasts to become "whole". because if he is the only one with the eternal mageyonkou sharingan so he wouldn't have any problems fighting anyone in the Naruto universe. If he has to come up with theese schemes it's because he lacks the power. I think that in a near future we will see how was the battle between the 4th and Madara and better understand the whole deal. In 100 mangas or such. LOL Also...didn't you at anytime considered strange that the eye Tobi has hidden is the same that kakashi has his sharingan? Don't remember ever seing both of tobis eyes. Madara could have possessed Obito's dying body for himself. . .Or used it to have a physical form on this side as he is probably not in this world...
As for the whole Byakugan Vs Sharingan Vs Rinnegan deal.... They are all diferent.
Byakugan can be call the "Truth eye" as it can see through intentions. One can call it also the "Live eye" as it can see the true life energy in a body: chakra. It should be the best aid in a medical ninja for example. Also, don't forget that Byakugan is more of a passive/defensive/support kind of bloodline eye. It alows the user to see throught any physical thing, intention, to control his chakra with a precision that no one else can and to have a type of 6th sense given by the (almost) 360? visual angle. Also it doesn't need much chakra to use and doesn't put any type of consequences to the user. Its the most usefull for support and defense.
Sharingan can be called the "Intuition Eye" as it can "predict" jutsu and the use of chakra to perform them. It gives the user the inate ability to understand every jutsu and to copy it. It however doesn't give the user the ability to perform any jutsu as that is dependent on the users own abilities. It can give a type of "intuition" alowing the user to have a perfect aim, perfect timing, etc. It also allows the user to use advance genjutsu and ninjutsu (especialy fire ones). It uses up greats amonts of chakra and can carry great stress to the user. If mangeykou it can take away the users eye sight and has a higher chakra need, but gives in return the ability to control certain unique abilities. All of theese pose great treat to the user and have great consequences. Also the whole "sharingan" deal is based on agression (fighting makes it stronger by learning knew moves/jutsus in battle, killing ones best friend gains another level and taking your brothers eyes gives you the maximum level) so I rate it as a "attack eye" with great consequences to the user. It's very useful in direct combat but useless in support.
The rinnegan is the (supposedly) strongest of all as it can controll live and death and all jutsu and forms of chakra. However as shown with Nagato, it seems to have a great connection with the other world and a type of "deal" with the "gods", giving ones live in return to having such power. It consumes a great among of chakra and poses great treath to the user. Its the stronger but also the one that has the greater amont of negative consequences on the user. It was supposedly the rinnegan that created jutsu and the ninja world. It is a type of "god eye". Capable of great feats....but only once or twice.
I don't think that they can be compared in battle. Nor one or the other is weaker. The Strongest in coombat is also the one that kills the user fastest...
Next 3 or 4 mangas will be stringly information and no action.
I still have a small hope that tsunade wakes up. And also that sakura learns anything new. She's the weakest one again. It would be nice if sakura learnt genjutsu or chakra storing like the 5th.
Greets...