Nintendo has announced a new slime version of the Wii releasing in Europe this holiday. This new slim Wii is a smaller design that is more suited to lay horizontal. The package comes bundled with Wii Sports and Wii Party. The only major sacrifice for the Wii going slim is the loss of Gamecube backwards compatibility. The system will not support any Gamecube software or controllers. Nintendo has only announced this system for Europe but you can expect this to come to North American shores eventually.
Source: Eurogamer