PBS | I, Cringely . April 20, 2006 – Native Speaker
The money quote.
Now for the interesting part: I believe that Apple will offer Windows Vista as an option for those big customers who demand it, but I also believe that Apple will offer in OS X 10.5 the ability to run native Windows XP applications with no copy of XP installed on the machine at all. This will be accomplished not by using compatibility middleware like Wine, but rather by Apple implementing the Windows API directly in OS X 10.5.
This would be great for consumers like me who want to run apps like Quicken for Windows or Windows XP games. Boot Camp and the various virtualization technologies have always seemed like kludges to me vs. a smooth OS X / Windows experience on one machine.
Vista won’t be shipping until 2007 so games will be written for XP for quite a while not only because of the delay in Vista but because of the huge installed base of Windows XP.