They say it is but i just don't belive it. Bill Gates said that some of the games will have to be recompiled, and now all of a sudden they are saying that every game will work. The old games were programmed to run on x86 and magically without any changes they will run on the PowerPc architecture.
M$ has some serious work to do if they are to make sure all the games are backwards compatible with the new system. Until i see it i just won't believe it. I develop software so i know what problems they will face, you don't so try and read up before you trust everything the giant tells you.
Why do you think you can't run windows application on Apple computers without buying the reompiled version? It is simply not compatible, it will be very difficult for M$ to have everything ready by November to have every game work. So i just don't believe them, i want to see what they have done in order to ensure the compatibility.