"After the demo was over Nintendo, bless it, treated us to a final element of cloak-and-daggerishness. We were told more facts about Wii U, which had to be read out and transcribed only onto paper.
So here they are: the console itself will run in full HD, via HDMI, but the touchscreen isn't HD. The console has internal Flash memory which can be augmented with "SD Card or USB solutions". It will play optical disks and downloadable content, and will be backwards-compatible with Wii software. And it will launch some time between 1 April and 31 December 2012."