i'm waiting for the subway to come back in stock too (i can dream, can't i? :P ) but in all honesty, because the rear expansion is used for so many devices... i'd prefer to put the usb ports where the joyports are on the A600.... ok if you're a righty a usb memory stick may get in your way, but for convenience its better there. you cant put it in the left side due to pcmcia and cd rom, idefix and CF card potential. only other option is on the rear on the top part of the enclosure, which then gives the problem of disconnection if you wanna crack open the unit in future.
you've got the added bonus that on a 1200 there is a nice little space where nothing is on the right hand side internally. to me, two usbs there like the joyports of a 600 makes perfect sense
EDIT - now we're running OT cos of subway. LOL.