Re: 599 - Tobi's indentity, 600 - something better?
599 - Tobi being revealed
600 - Kakashi going nuts and learning s/t ninjutsu
Whoa, I surely would love to see this happening!
Edit: Seriously though, what's with all this "OMG, sth big is gonna happen in 600th chapter!".
You guys really made it up. There was no pattern of something epic happening in X00th chapters.
Chapter 100 - beginning of Naruto's fight against Neji, ends with Naruto trying to attack him (In 101th the attack is shown to be ineffective)
Chapter 200 - Kimimaro appears for the first time in manga, in the last pages of the chapter. Nothing epic, either.
Chapter 300 - Team Kakashi finds Sai's image book and tries to decypher it.
It's true that in chapter 400 and 500 are flashbacks and stories explaining some stuff from the past. Still, it could have been a coincidence. There are many epic stuff that could be put into X00th chapters, so it's pretty possible this wasn't intended.