Wii U

Using this until the final name is known.

Rumors started hitting in a big way: 2011-04-14

Officially announced: 2011-04-25

Before official name known, usually referred to as Café; apparently Project Café being its codename.  There were some apparently incorrect rumors of the final name being something like Stream, Current, or just plain "Nintendo".

Official reveal of controller and Wii U name at pre-E3 press conference: 2011-06-07