Your Wii U is not patched. No Wii U is patched.

Yes it's true, all Wii U's are vulnerable, and Nintendo is even still actively selling entry-points that allow you to access homebrew persistently.

What's an entry point?
The Nintendo DS emulators on the Wii U eShop are vulnerable to an exploit called haxchi.

For now, the site ain't much to look at, so give these links a look: