Heh I wrote off the "Uchiha Madara?!?" exclaimation as poor manga translation. Kakashi's accusation was "the check" to make Madara admit exactly who he was, because there still was question as to who "the man in the swirly mask" was.
Just like the situation in "Avatar the Last Airbender" when Zuko's Sister confronts Zuko by saying "You've been to see Uncle, haven't you?!" Zuku replies "That guard told you" and his sister retorts back "No, you just did, you moron". But I digress.
Dang.. can't wait for the next chapter.