According to retail sources, Nintendo Memory Cards may be sold on a one to one basis.
It's a well known fact that the GameCube needs memory cards to save game information. So, when you purchase your GameCube, you'll need to get a memory card with it. Tendo Box has heard from retail sources that the standard Nintendo Memory Card 59 will be shipping in a 1 to 1 ratio with the GameCube. What does that mean, exactly? Well it means that for every GameCube shipped, one Memory Card 59 will be shipped. According to Tendo Box, most retailers will also only be selling the Memory Card 59 on a one to one basis. So unless you plan on buying more than 1 GameCube, you won't be able to get more than one Memory card 59.
But don't worry about a massive shortage. More memory cards will become available a week or two after launch. Of course, if you really need more than one card at launch, there's always 3rd party memory cards (if you can trust them).