A GB of data used to be a huge amount. It seems only a few years ago that I had a 40 GB hard drive in my computer and it never seemed to fill. Now I'm fighting with a TB of data and I still struggle for room. Perhaps that's why people are a little confused as to why the Wii U has only 8 GB of internal storage.
Presumably to keep costs down and make for an easy transfer/management system, Nintendo are opting out of giving their next console anything even close to the space available in competitor's consoles. Instead, you'll be expected to use SD cards, USB pens or internal hard drives. If it means we can knock a small amount off the overall cost, does this really matter now that flash drives are coming down in price?
Something tells me that, for some people, this will be a big deal and that Nintendo will eventually cave to the memory war and release a new Wii U with increased internal storage. For those of us with multiple external hard drives hanging around, well, I can see the advantage.