As I suggested in my review of Steve Jobs' keynote at MacWorld SFO, Apple is clearly throwing stones into Microsoft's garden. This is brilliantly nailed down by Robert Cringely.
Now, er when all the announced goodies will be available and not in beta versions, one can get to do a whole bunch of stuff on a computer without a single Microsoft software. It's time to do some math, but considering the price of MS Office alone, I bet there are now more viable scenarios where the TCO of a Windows PC is significantly higher than of the Mac.