Though it was confirmed that the Wii U would indeed play the original Wii game disks, it will not be so friendly to the previous generation.It is pretty common practice for the this generations of game consoles to be only backwards compatible one generation(certain model PS3s are the exception), this is still disappointing news for many who want to finally get rid of their Wii for the upgraded model.
Also, some have speculated they may be able to bring it back with a firmware upgrade, but I am sure that if it was possible for the Wii U lens to read GC games Nintendo would have let it.
Source: Joystiq
