@Parokki
I would have to guess Scenario 2. Scenario 1 looks to have about a 10% chance of happening with Scenario 3 having about a 2% chance of happening. Not many third party devs are going to go exclusive for the Wii, especially when the 360 outsells the Wii easily in the software department, look at the attach rates, and then for Wii's attach rate look at how many games are made by Nintendo, I wouldn't want to jump into that 'exclusively' if I was a third party dev but I would most definitely make all my games that I could multi-platform.