The 3DS XL has sold an estimated 193,441 units in its two days on the Japanese market, according to an Enterbrain report published by Famitsu. New Super Mario Bros. 2, which was released concurrently, sold an estimated 430,185 copies. It's unlikely that number includes sales of the download version, which was launched at the same time. There must have been at least some eShop copies sold.
The original 3DS reportedly burned through its full initial Japanese shipment of 400,000 units in 24 hours, making the upsized unit's launch softer in comparison. The PlayStation Vita, the 3DS's most direct competition, sold321,407 units in its December 2011 launch in Japan, though sales have slowedquite a bit since.