Hacking System Update released today... does it do anything to homebrew?

[Maxternal]

If this is the same as the original Wii, I understand they used the same address for the shop channel as they did for the updates. If that's also true of the Wii U that could cause you some problems.

 

[asper]

http://nus.cdn.shop.wii.com

You can also try to disable download in the settings options (wrench icon) under the Download Management tool:

but download will be probably resumed when the console is re-started (need to test, no download at the moment).