@cobretti2 and dannesandin
I think the 8GB flash is purely for users who have no interest in digital content.
I think Nintendo will have a 'PRO' model with a usb drive packed in and/or clearly advertise the need for a USB HDD if you decided to use the digital model.
Its also the best solution. Quite a few people will be perfect with very little storage. Me and those of us on this site will likely buy a $50 massive USB HDD. I know for that price I can find just under 1TB and very shortly 1TB+.