Sega games on a Nintendo console here in America? That is correct. The ESRB has rated two Sega Game Gear games for Nintendo's 3DS.
The Game Gear games are Sonic the Hedgehog Triple Trouble which happens to be a favorite of mine and Shinobi. Both have received an "E" for "everyone" rating.
For those of you that are not up on your handheld knowledge, the Sega Game Gear was Sega's take on the handheld craze that released here in the states in 1991. Sega officially dropped support of their handheld in 1997 after an unsuccessful shelf life in Japan and issues with the handheld's battery life became more prominent. The original model would only last for about 4 hours. Sega Game Gear games are available in Japan for the Wii through the Nintendo E-Shop.