The following news is best taken with a bag of salt and should be considered a rumour. TFW2005.com are reporting that their Transformers Revenge of the Fallen "insider" has told them of the vehicles that will combine to form Devastator in the Transformers sequel. The vehicles are:
O&K/Terex RH400 - Hydrolic Mining Excavator - (red)
Caterpillar 992G - Wheel Loader - (yellow)
Caterpillar 773B - Dump Truck - (green)
Mack Cement Mixer - (silver/white)
Komatsu HD465-7 - Articulated Dump Truck - (red)
Kobelco CK2500 - Truss Crane - (yellow)
Caterpillar D9L - Bulldozer - (beige)
Though TFW2005 do have connections to Hasbro, with members of the Hasbro team reportedly posting on their message board, and Roberto Orci posts on their, it is also possble that they are working independantly or with Paramount Pictures to create false rumours and/or are receiving false information via a deliberate "leak" to try to keep the hype going surrounding the film.
Again, no further information onn their source has been released.