TFW2005.com have run an update on their Roberto Orci thread containing a few more pieces of information, or non-information.
In this latest batch of answers, he confirms that there are no triple changers in Transformers: Revenge of the Fallen. Talked about it. Does a combiner count? We figure a triple changer is a good idea for part 3. (Obviously this is just conjecture on the third film)
Also covered in this round of questions - it is "certainly possible" that we will see more bickering between Megatron and Starscream, there will be "some more emphasis on the Transformers", and Roberto and fellow writers Alex Kurtzman and Ehren Kruger have "talked about" the possibility of Optimus Prime combining with another robot or even his trailer. You'd certainly hope there would be more focus on the Transformers in the second film.
Regarding Soundwave's alt mode Roberto's response was: I don't think so, but I haven't seen all the guesses.