Madara is Mister Know it all..haha... I was wondering the same thing Bro. That technique was still imperfect during the time of 2nd Hokage. Yet Madara has figured out way to get out of that technique. Yet I wonder, if Madara knew about Edo Tensei so much, why was Tobi acting Dumb and all? It gives whole new perspective about Tobi's Identity.. If not for others, then for me(at least)..
Further, we all know that unless Madara has some kind of Flashbacks about him, Hashirama and others(like Tobi), Madara ain't going nowhere.. Seems like that time might as well coincide with Breaking of Tobi's Mask..
The Biggest question raised(in my opinion) in this chapter is: How the hell are these near death Kages gonna be able to defeat an unbeatable Monster? Unless Naruto or others arrive, Kages are gonna get annihilated. Will Hashirama arrive?(Maybe Yamato will fuse with that Mindless Hashirama Plant and rescue Kages..) Can't wait to see the development...