Over at OS Attack they have noticed that Microsoft has inlcuded AeroSnaps in the next version of Windows PE that comes with Windows 7. This is a good indication that there have been other things added to the new PE as well.
Via: OS Attack
UPDATE:: It appears as if all of the standard shortcuts for AeroSnaps that work in Windows 7 also work in Windows PE.
Maximize Keyboard shortcut: WINKEY + UP ARROW Maximize vertically Keyboard shortcut: WINKEY + SHIFT + UP ARROW Snap to the left side of screen Keyboard shortcut: WINKEY + LEFT ARROW Snap to the right side of screen Keyboard shortcut: WINKEY + RIGHT ARROW Restore Keyboard shortcut: WINKEY + DOWN ARROW