The 3DS will be turning a year old soon, and
IGN recently talked to Nintendo's Executive Vice President of Marketing and Sales, Scott Moffitt about the portable’s success in the United States.
IGN wrote:
(Figures provided for the DS are after that system was on sale for one year.)
•The 3DS has sold 4.5 million units, compared to the original DS's 2.3 million.
•With a library of over 100 physical titles, the 3DS has sold 9 million games; the DS sold 5 million with 58 titles.
•The eShop, which wasn't available in the DS's first year, has over 500 games available. Nintendo wouldn't provide sales statistics, but did mention that on average a consumer downloads five games or programs.
•In terms of general revenue, including software and accessories, the 3DS has generated $1.2 billion; the DS managed $540 million in its first year.
Three Nintendo titles have also enjoyed strong success on the 3DS. The 3D remake of The Legend of Zelda: Ocarina of Time has sold 900,000 units. Super Mario 3D Land and Mario Kart 7, meanwhile, have both cleared 1 million units sold, with 1.75 million and 1.4 million in sales respectively.
The numbers are amazing, especially considering the 3DS' slow start. (Keep in mind that these are stats from the US only.)

Finally
Nintendo has confirmed that Game Gear titles will be hitting the 3DS this March Break. The titles that will be launching on March 15th will be Sonic Triple Trouble, Shinobi, and Dragon Crystal. Also, Punch-Out!! Featuring Mr. Dream will arrive on March 8th. A demo for Sega's Rhythm Thief & the Emperor's Treasure will be coming on April 18th, and Colors! 3D will be available for download in the same month.