So finally it's revealed. The reason why Itachi killed his whole clan was to obtain the Mangekyou Sharingan. And the reason he let Sasuke live was so that he could do the same. From the chapter I would assume that to get it you need to do this "special condition" their father mentioned. Killing your best friend would be measured the same as killing your family I guess.

...

Damn, that wasn't as deep as I expected it would be. But still, good stuff.

AND HELL does Sakura's ass look fine on the first page.