With the introduction of the new GMT900 series of full-size trucks coming early next year, it's time for the speculation to begin. Word has it that the changes will be "evolutionary", or "change what's broken and leave the rest alone". The sheetmetal will be all-new and should provide more differentiation between Chevy, GMC, and Cadillac models. Arguably the largest problem with the current line-up is the interior, which should be much improved as is the trend with newer GM vehicles. Let's just hope they can add a bit of style while bringing a level of durability that's appropriate for a truck. Where significant change won't take place is under the skin, as the basic layout and execution of the GMT800 remains competitive (if you don't think so, please feel free to suggest changes in the comment section). On the powertrain side, six-speed transmissions come first with hybrids appearing around '08, and expect more power all around the engine line-up.