November 18 might be the day, but we're not buying the validity of this rumor.
Yesterday, Wii U Daily posted a story saying that Wii U was coming out on November 18, according to a Japanese retailer source. It's a rumor, and while that very well may be the date the Wii U comes out, this isn't ground-breaking news. It's dealing mainly in the obvious. After all, the Wii, GameCube, and DS, along with every marquee Nintendo title ranging from Skyward Sword in 2011 to Metroid Prime in 2002, came out on the Sunday before Black Friday.
As Kotaku accurately pointed out, Wii U Daily also posted a story about a Rockstar financial report revealing that Grand Theft Auto V was coming to Wii U in 2013. That sounds like pretty huge news, and the fact that this financial report wasn't a bigger story makes it seem like it's nothing more than a pie-in-the-sky rumor. Though Wii U Daily contacted Kotaku saying that other sites posted this news, but the other sites sourced an analyst report, which is almost the complete opposite of hearing it right from the company who is making the game.
So, while the Wii U is most likely coming out on November 18, don't prep the champagne just yet. Let's wait until Nintendo says it officially, or we get a rumor from a viable source, such as Nikkei. Basically, hold on to your hats come E3 2012 in June. Or get pumped for that one day where there's a deluge of rumors like last year.
Also, on a side note, you can listen to an episode of Connectivity from the beginning of the year where I state several times that the Wii U is coming out on November 18.