This Saturday and Sunday (July 20th & 21st) a bunch of Gamestops across the States will be demoing Pikmin 3. Also during those days if you pre-order a digital copy of Pikmin 3 there you will be able to download it to your Wii U a day before it releases in North America. It releases on August 4th but you can get it a day earlier digitally if you pre-order the digital copy of the game.
See the locations near you for each day here:
http://www.gamestop.com/EventsThis was covered in the Nintendo Direct Mini I didn't post about yesterday that also confirmed that Earthbound was on the Wii U VC yesterday.
Source:
http://gonintendo.com/?mode=viewstory&id=207775They also may give a sneak preview of an upcoming 3DS game there.