This is from superherohype
Source: MTV March 13, 2007
Transformers screenwriters Roberto Orci and Alex Kurtzman talked to MTV about the anticipated film and also a bit about a possible sequel:
Kurtzman: As fans, we read that [first draft] and said, "This isn't the best use of Soundwave, so let's save him for when we can actually do Soundwave right."
MTV: It sounds like you're already thinking about a sequel.
Orci: We have ideas, but we're trying to be diligent about not thinking ahead. We have a few notions.
MTV: Would any of the later incarnations of Transformers from "Armada" or "Beast Wars" be involved in future stories?
Kurtzman: Sure. Everything is up for grabs. But you have to be careful to not mix too many of the iterations. We couldn't crossbreed too much.
They talk a lot more about Bumblebee and the film's big third act, all of which you can read here.