my, my, how far we have strayed from the original question. The topic that you all are discussing now is nothing new. I seem to recall an arguement like this one in a bleach vs. naruto thread and a few others as well.
There is nothing such as fairness in ninja warfare. There is only victory.What I mean is the completion of one's mission by any means necessary. Look at some of the techniques they use and i think you will see what i mean.
As far as who is stronger Orochimaru, Jiraiya or Itachi. The answer i came up with is; they all are in there own way.
There have been two fights that we have seen so far between Orochimaru and Jiraiya. Both of which Orochimaru seemed the victor. The first was when he was leaving the village and Jiraiya was trying to persuade him. Jiraiya was not trying to win that fight he was only trying to save his friend. The second we all know was between Tsunade, Orochimaru and Jiraiya, not that i think that really showed there true power.
Itachi and Jiraiya came face to face once, and that is when they tried to kidnap Naruto. Jiraiya used a technique that had never been defeated before, and Itachi used another one to counter it and run away.
When Itachi said the best possibility that they can hope for is that they die taking him down with them (something to that extent). I believe that they were talking about Jiraiya, because Kisame was already there to deal with the chakra problem, as we have seen. That is the reason i believe those two were paired together. If they were powerful enough to take on Jiraiya they wouldn't have had to distract him or run away when that failed.
Itachi's power lies in his sharingan and his brilliant strategies not to mention that he is gifted in fighting as well. But i believe is feared Jiraiya because like he said the only way to defeat him to die taking him down. This i think is from the time Jiraiya was hailed as the "Hero of Konoha" and when the legendary Sanins were born.
Orochimaru i say is powerful as well, why? He controls Manta and for him to do that it shows that he is powerful. For Manta to be taken down, it took Bunta, Jiraiya( at a third of his power) Tsunade and her animal, I forgot her name....
Until there is an clear and decisive battle i will leave it at that. They all are powerful and all have there advantages.
Now back on topic I honestly can't tell you anything. But we all know that he is connected to him in some way, because if i remember correctly the fox demon was stopped before he entered the village. You have got to admit for the little we have seen of the fourth he does look like Naruto or rather Naruto like him minus the fox whiskers mark on his face, which i assume it is due to the fact that the demon fox sealed inside of him.
Just be patience and wait, all will be revealed in time, or atleast enough to allow specluation.