NPD's top 25 includes at least eight 3DS games
The NPD told Joystiq that "some examples" of the 3DS titles that made the list include Skylanders: Spyro's Adventure, Mario Kart 7, Super Mario 3D Land, FIFA Soccer, Lego Star Wars 3: The Clone Wars, Lego Pirates of the Caribbean, Resident Evil: Revelations, and Mario & Sonic at the London 2012 Olympic Games — the last two on that list being February releases.
That's ... a significant portion of the top 25. It's also evidence of a reasonably engaged 3DS install base, and therefore stiff competition for the PS Vita, which came out in February. The Vita's Uncharted: Golden Abyss placed somewhere in the top 20 (at least in retail; Vita games also have digital sales not charted by NPD).