2DBoy have given an update on the proposed retail version of World of Goo that was supposed to hit Europe (and Australia), bringing with it an extra chapter. Unfortunately, it looks like it will not be happening. They decided that the added content was unfair for those who had already purchased the game - so it's going to be kept as a WiiWare release. World of Goo will hit the Virtual Console shelves some time in December. .
Source: 2dBoy.com