Nintendo has had a bit of an image problem over the past couple weeks, with the company's Laurent Fischer dismissing complaints from Wii fans about the console's lack of storage by saying it was only "geeks and otaku" who would be interested in such a thing. He's since apologized for his remark and in a recent interview said they are actively working on a solution for the Wii's data storage limitations.
The Wii currently offers 512MB of internal flash memory for saved games and downloadable content, but following the launch of the WiiWare games channel many have already exhausted the console's internal storage. Though the Wii is expandable via SD Cards, it can only execute downloaded code if it is stored within that internal 512MB block.
So, a new hard drive add-on for the Wii is coming then? Well, no. Fischer denied plans for an external hard drive, but said a solution that is "very linked to [Nintendo's] overall strategy" is being developed by their team in Japan. Exactly what the solution will be remains to be seen.