If bundled Nintendoland is not included, this actually puts Nintendo pretty close to Iwata's numbers. Assuming 75% are deluxe sets, 2.4+.75 = 3.15 games per consol from pre-orders alone. Surely most owners will pick up one more title before March, and we can be absolutely sure that most stores will have in stock a game for every WiiU buyer, so Nintendo may actually exceed projections.
Also, I think the reason for the great attach rate is that there is a "killer app" available at launch that almost everyone will want: New Super Mario Bros U. That and a much, much better selection of 3rd party core games than Wii.