"What is it? I just can't tell you"

What this could mean is anyone’s guess but as we’ve said in the past it’s doubtful that Nintendo will just allow you to plug any old hard drive in via the USB ports – the more likely option is that the company will produce a bespoke peripheral that will store the games and the games only, or something along those lines. Nintendo isn’t a corporation that is keen on letting a money-making opportunity slip through its fingers, after all.

Shigeru Miyamoto was interviewed alongside Reggie and confirmed that an announcement on the storage problem is to be expected soon.

Source: GoNintendo