I saw the matrix-spoilers

[GameMaster]

As far as the giant face goes, who was talking? Did the voice of the giant face belong to the leader of the machines? Do the machines even have a leader? If so, who is it?

Also, when Agent Smith "infects" Neo and turns him into a Agent Smith copy, is it Neo that summons the power to destroy Agent Smith as well as all his copies, or do the machines (or the leader machine if there is one) send power through Neo's real body to destroy Smith and all his copies?

And... are there currently any plans for a fourth movie because I want to know if Neo is dead?

Also, I still don't understand how Agent Smith transferred himself into the real world in that other guy's body who was in a coma as well.