Okay, let's set this straight: Marco Minnemann is NOT the new drummer for Dream theater. they still have to announce the new member.
They do have a new drummer but they want to and I quote: "Spending some time together getting everything in order before making an official announcement"
Here is the full quote as written on Blabbermouth:
Guitarist John Petrucci:"Auditions went great and we do have someone but we are spending some time getting everything in order before making an official announcement. Let me just say that we are all incredibly excited about our choice and just bursting at the seams to let the world know."
Well, I think that we all should stop guessing and wait for them to clear this all up.