Tantric has released libwiigui, a GUI-making library.

libwiigui is a GUI library for the Wii, created to help structure the design of a complicated GUI interface, and to enable an author to create a sophisticated, feature-rich GUI. It was originally conceived and written after I started to design a GUI for Snes9x GX, and found libwiisprite and GRRLIB inadequate for the purpose. It uses GX for drawing, and makes use of PNGU for displaying images and FreeTypeGX for text. It was designed to be flexible and is easy to modify - don't be afraid to change the way it works or expand it to suit your GUI's purposes! If you do, and you think your changes might benefit others, please share them so they might be added to the project!

Download here --> http://code.google.com/p/libwiigui/downloads/list