Provided you downloaded the lengthy system update during the initial set up process of the console, all your previously bought Wii games and accessories (such as remotes and the Wii Fit Balance Board) will be compatible with the Wii U. Even the attachments such as the Nunchuk and Classic Controller will work just fine, and be sure to transfer over all of your Wii content to the Wii U too via an SD card. However, if you’re looking for more remotes and/or Nunchuks, then they’re still available at all good retailers, but this time they’re branded with the Wii U logo. Better yet, all new remotes will now have Wii Motion Plus integrated in them too for better motion accuracy, which is required for a lot of the newer Wii/Wii U games (such as Nintendo Land) these days.
Additionally, Nintendo’s also made available a more traditional style of gaming controller called the Wii U Pro Controller. Set in a comfortable form not unlike the Xbox 360’s controller (although the placement of the right thumbstick and face buttons have been switched) the Pro Controller was designed for those looking for a more traditional gaming experience, such as in CoD: Black Ops II. In fact, if you’re planning on getting Black Ops II it might be a good idea to pick this guy up as well. With more great games to come and some strong third-party support you might want to future-proof yourself now for when the big guns come rolling in.
And one last thing: if you need to expand your storage (if you bought the Basic package, chances are very high that you eventually will need to) Nintendo have made a simple solution available. The Wii U’s storage capacity can be increased by any self-powered external hard-drive (one that doesn’t draw power via USB), meaning you could have a 2TB drive plugged in if you so wish. The only downside is that the entire drive will need to be formatted via the Wii U, and once that’s done it will no longer be compatible with any other computer or device (this is a piracy countermeasure to prevent the exchange/distribution of copyrighted data). So be sure to use an external HDD that you don’t plan on partitioning/sharing between devices, and instead pick one up for the sole purpose of it being attached to the Wii U.