the strongest ninjas alive? probably!
but remember what madara/tobi said about the 'chosen' descendents of the sons of So6P...
i think madara and hashirama could have been even stronger, but there's still some time to develope for sasuke and naruto.
No way were hashirama and Madara stronger than Naruto and Sasuke. What is the only thing hashirama had going for him? Mokuton and good genes. Madara had EMS.
Naruto has two power modes that are just insane, and more normal chakra then almost anyone. He also has completely mastered the rasengan and is a great wind user. With the use of his clones he can master any jutsu in hours or days.
Sasuke has EMS and has almost completely mastered two elements. Well he was helped out mostly because of his KG but still so were Hashirama and Madara.
But still Sasuke can go toe to toe with anyone now and guess what? He and Naruto are only 16. They only became genin at the age of twelve and only seriously started training right before the time-skip. At the rate they are going they will become stronger than anyone else in the history of their world. If they have time to actually devote to training then they will become unbeatable and unsurpassable except by each other.
EDIT: I praised them alot but I also don't think they are the best ninjas yet. They are only skilled in a few of the areas of being a ninja. Neither of them really has any skill with genjutsu, sealing, they don't have a large variety of jutsus, and have no real knowledge of other jutsus so as to formulate good strategies. Right now they are kind of just rushing in and planning as they go. They often get hammered at first and then come back and pull off some variation of an already attempted attack.
I personally think that Nagato, Minato, and Itachi are better than them.
Jiraiya and Oro are right beneath Naruto and Sasuke but that is only in ability to win fights. Overall they have way larger skill sets and masters of basically all areas (except genjutsu again, which almost no one uses for some reason)