Alright, I'm a Mac zealot, I admit it. I love OS X, I love Apple, and I want others to see the same thing I do. When the inevitable potential switcher comes to me and says "I was thinking about switching...but if everything is going to be different in 18 months, I don't thing I should" What do I say? Sure, I can say there will be strong emulation that will work both forwards and backwards. The programs you buy now will still work then, and you'll still be able to use the new programs that come out in a couple years. But that doesn't sound so positive.