The Xbox 360 has a brand new motherboard. Dubbed the Jasper, it presumably has a new 65nm process GPU. The new box has a 150W power supply instead of the former’s 175W brick. They’ve changed the plug design to prevent usage with old consoles. The most notable change is the onboard flash memory upgrade. Earlier consoles only had 16MB; new ones have 256MB. The majority of this storage will be used for the new dashboard, the NXE. The remaining space can be used for game saves. With the new storage, Arcade units are no longer including memory cards. You can see more images of the boards on Xbox-Scene.