I was utterly dissapointed to see Galactus reduced to a mass of colorfull storm clouds in F4 2, and would absolutely hate to see this happen to Unicron.
I doubt Bay would do something like that, but now's the best time to throw some ideas for the "Unicron" Character which we'll most likely see in tf3... if at all.
Unicron was like the Deathstar x 10 in cool factor
I like the way the autobots did battle inside unicron, and would like to see this happen in the big screen.........Whether or not the Matrix plays any part in the movie, I don't care....same with the quintessons. Those evil easter eggs are in need of a massive makeover if they should appear on the big screen...
anyhow...I think Unicron should retain the "Horned helmet" look...just with a modern touch