Wii U firmware version 5.1.0 should be streaming out to consoles worldwide as I type this. This update finally, finally adds the ability for a system transfer--that is, you can offload all of your digital purchases, Mii information and Nintendo Network ID to a brand new Wii U in the comfort of your own living room.
Until now if your console bricked or was otherwise broken you had to send it in to Nintendo to get your data transferred. This was pretty frustrating because it defeated the whole idea of the Nintendo Network ID, which was to have a unified login system like PSN or Live for just such this kind of situation.
I'm a little annoyed that it took nearly two years to get this problem squared, but then again I can't be too angry with Nintendo as it's an issue I've had with the competition for a long time too. I still can't get all my Rock Band songs and their inane permissions transferred to my newer model Xbox 360, and any time I've had to do any kind of data swap between 360s it was an enormous pain in the butt requiring convoluted procedures, multiple email verifications and passwords I'd forgotten years ago. As far as I'm concerned Sony is still king when it comes to ease of data transfer.
Anyway! Aside from the much-needed data swap update, this new firmware also lets you browse the Wii U eShop using Wii remotes, Pro Controllers or Wii Classic Controllers. This is a welcome change; before you had to put down whatever controller you were using and switch to the GamePad, which could be pretty cumbersome. Nice improvements across the board this time, even if they are way overdue.