A lot of people complained that Nintendo only showed the launch window titles for the Wii U at E3 2012. This was what should have been expected, but even so, Satoru Iwata has shared that:
…because we are now in the era when similar proposals can be made by the others just one year after we introduced a brand-new hardware system proposal, please understand that we really can’t say much about what else we are planning.
In other words, “people are copying us, and we don’t like that”. And, just to clarify:
…what we’ve shown at the E3 show are both the launch titles that will be released with Wii U hardware this holiday season and the launch window titles that will be released early next year or not long after the hardware launch.
So everything we’ve seen so far is stuff we’ll be playing in the not-too-distant future.