Nobody has any other guesses on this? Not to take anything away from the imminent software announcements Nintendo surely have planned, but the possibility of new hardware always intrigues me. A few things struck me while pondering the "Advance" trademark.
-Nintendo has stated that they will announce their NFC plans at E3.
-Iwata has pledged to double down on the Gamepad
-There is to be no new hardware unveiled at E3
-This patent just surfaced
Maybe I'm connecting the wrong dots here, but I believe we might be looking at a Gamepad redesign. Nintendo being Nintendo might not be content in just releasing a ripoff of Skylanders, so they're taking it to the next level by using the figurines to actually control (or "advance") your character. The figurines and other controller mods would be part of the "Advance Series" and the "One Push Button" or other button configs described in the patent would be dubbed "Advance Push."
Not sure if Nintendo packs in the redesign with every Wii U at the start or if they sell it separately as a second controller in their bid to "double down" on the device. If their flagship software for this line is a multiplayer game (which you can pretty much bet on), that might be all Nintendo need to justify selling another (redesigned) Gamepad. The "Advance" moniker could also aid in selling the message that this is a control method for advanced players who like to customize their layout.