Apparently, the new redesigned Wii model is currently only official in the UK. I'd be really surprised if it didn't make it to other territories.
I wonder how much of the parts are changed in this revision. Did Nintendo just remove the Gamecube ports? Are the parts modified to no longer handle Gamecube games (i.e. No GCN mode in the chipsets, the disc drive doesn't accept GCN optical discs)? Maybe that could shave off some manufacturing costs. I'm not claiming it does; just speculating.
Seems odd to introduce this so late in the life cycle though maybe Nintendo is trying to jump start sales with a new model, even though, from the one picture, it looks exactly the same besides the repositioned logo.