Via Andriasang: Kojima Productions' Jiroo Tsubuyaki revealed (don't bother clicking if you don't read Japanese) today on Twitter that a Metal Gear Solid-themed 3DS bundle will be hitting Japan, presumably around the time MGS Snake Eater 3D comes out on March 8.
The previous 3Ds bundles have been quite nice (Mario and Zelda), so we've got no reason to expect anything less from this one—especially if traditional Metal Gear Solid artist Yoji Shinkawa is involved. You've seen his work (example above) on the series' covers.
We can't discuss this without mentioning the Snake Eater 3D Accessory Set, which tricks out your 3DS in all kinds of Kojima-ey goodness. Check it out and let us know what you think in the comments or on Twitter or Facebook.