... but Windows, as an organization, is infinitely more open and transparent than Apple.
Microsoft wants to be more like Apple. Apple makes a lot of money.
Windows 8 looks to be about splitting Windows in two parts. Windows used by businesses. Which need programming. And Windows used by consumers. Which needs apps.
Build is likely to be about how to write apps that will be sold thru and deployed by Microsoft onto the consumer windows desktop. A great opportunity for programmers to make some money. But I would not expect a programming paradigm breakthru. If anything, there will be more than a few restrictions regarding what your app can do and how much access it has to the resources of the PC.