Nintendo has attributed the lack of "new key titles" for Wii to "preparation" efforts for Wii U.
Besides the upcoming Legend of Zelda: Skyward Sword, the only notable Nintendo-made Wii games of 2011 are Kirby's Epic Yarn and Wii Play Motion.
"Strong momentum is very important for game platform businesses and a strong software line-up to vitalise a platform is necessary to maintain this momentum," Nintendo president Satoru Iwata wrote in a half-year financial briefing.
"In the first half of this year, however, we could not make the continuing sales of the first-party software released last year as we had planned, nor, in the course of preparation of the next platform, could we release new key titles for the existing platform in a timely fashion due to completion delays until the latter half of this year."
A number of questions surrounding Wii U remain, despite developers receiving updated Wii U dev kits this summer. Just how powerful is Wii U? And what can it do online?
We'll find out next summer, apparently. "We would like to show the final format of the Wii U at the E3 show next year," Iwata announced.
He went on to offer update on a Wii U release date.
"We are also planning to launch the Wii U, which is the successor to the Wii, during the next fiscal year," he wrote.
Nintendo's financial year runs from April 2012 to March 2013. But the absence of Christmas 2012 from his vocabulary suggests Nintendo may intend to use those final three months, January to March. The 3DS launched in Japan in February, and in the US and Europe in March - is Nintendo planning something similar for Wii U in 2013?
Perhaps - but Iwata is adamant that the Wii U arrival will not suffer the same setbacks as the 3DS did.
"As we learned a bitter lesson with the launch of the Nintendo 3DS, we are trying to take every possible measure so that the Wii U will have a successful launch," he pledged.
Nintendo yesterday revealed a big financial loss for the first six months of its financial year (April to September). This in turn led to the company predicting its first full-year loss in decades.