On March 20, Nintendo will be realeasing 2 new colors for Nintendo 3DS in Japan. The colors are light blue and gloss pink.
An added feature will be a 4GB SD card instead of the 2GB SD card which was included in the older model.
There is still no news on if or when these models will be coming to the U.S.
Apparently, the price will remain the same as the original system.
Source: New colors for Nintendo 3DS