That's right. The dynamic duo of Transformers and Transformers: Revenge of the Fallen aren't coming back to screenwriting duties, it's all Ehren Kruger. Orci posted his and Kurtzman's status in response to a fan's question at Don Murphy's board:

So Bob and Alex is it true. you wont be involved this time round.
It's True

Sorry to hear that Roberto, really I am. Are we in good hands with Mr. Kruger? Does he know his Transformers?
He does. He really did his homework. He's awesome.

Head on over to Murphy's to read his post, as well any other answers. Sound off your thoughts here.