--> This would be about 25cm by 10cm, so still portable, just not pocketable.
--> More USB-A ports seem sensible
--> Using the same battery compartment as the pandora seems an obvious move.
--> The battery has two advantages: charging your pandora, while using it on the train (or something) without rebooting, and providing a powered hub while traveling
--> No, I am not left handed, but the extra touchscreen could behave like extra buttons for programs that require them, or as shortcuts. For some applications it you could put frequently used controls on there (used with left hand) while you used a usb mouse/etc with your right hand:
For example, I hacked a separate numpad together out of one of
these (operated by my left hand), I find it very useful for entering numbers in boxes.
Also, I'd love to see what people could come up with to do with it (other than DS emulatiion

)
Might be good for graphics work too...
--> an e-SATA bay could be interesting. What exactly would you do with it?
EDIT: missing S