Digital Foundry has a great breakdown of the image, which appears to exhibit the motherboard of a DS test kit or development kit. The tech site points out that one of the screens adheres to the 4:3 aspect ratio of current DS models, while one screen appears to be substantially wider. If this is a stripped-down version of the 3DS, this could indicate that only one of its two screens uses 3D display technology.
Also worth noting is the "CTR" designation the hardware is given in the FCC listing. As Digital Foundry points out, each model of the DS has had a three-letter codename for internal use: The DSi was called "TWL," the DSi XL was called "UTL," and so on. CTR is a whole new callsign, which may indicate that this is a whole new piece of hardware. We've contacted Nintendo to see if we can get a comment on the filing -- at the very least, we should learn the accuracy of this speculation during Nintendo's E3 press conference on June 15.