The Nintendo DSi units available in stores right now might be the last ones ever made. A retail source has told Kotaku that Nintendo has stopped production and that the company is getting ready to clear out its stock of the system. Nintendo DSi XL, the DSi's big brother, is still being made though.
The reason is probably the 3DS, which will be released soon. Too many similar machines might confuse consumers and make retail chains less likely to buy them.