Revealed earlier today was the head shot of Sideswipe, and just now, the full body shot animation model, with some details of its features.

http://tformers.com/transformers-rot...0708/news.html

The Animation model and the silver car seen in filming should mean that Sideswipe should be a definite cast member. A sleak silver Autobot makes me think of Jazz from the first movie, and would make it difficult to see Jazz returning without confusing people with two similar looking bots on screen and toyshelves.