Posted in 2 parts, an interview with the Transformers Voice Actor that is just as reveared by fans as Peter Cullen.
Frank Welker had suplimentary roles with the first movie (in the game and prequel story), and could well be featured in the second movie if Bay decides he is suitable.

http://www.tfw2005.com/transformers-...1-of-2-167015/

http://www.tfw2005.com/transformers-...2-of-2-167034/