Will it be a "tweak" of Windows 7, or a radical overhaul? Will it be small and light, or massive and bloated? Will the interface be more like Windows 7, or Windows Phone 7? Will it come with Skype?
Of all the unknown unknowns, to borrow a phrase from Donald Rumsfeld, here are the 5 biggest questions:
An Intel x86 compatible version called "Windows 8 traditional" (the software equivalent of "Coke Classic," apparently) will run existing Windows applications but only in a "Windows 7 mode." And of course it will also run shiny new Windows 8 applications yet to be created.
Four additional versions will support four distinct types of ARM devices, including tablets, phones and other devices. These ARM versions will neither run Windows applications, nor offer any sort of "Windows 7 mode" that would enable the use of existing applications. Not only will Windows 8 ARM apps not run on Windows 8 Intel devices, apps written for one of the four ARM variants will not even run on the other three, according to James.
While some ARM-based phones and tablets will be incompatible with other versions of Windows 8, James assured investors that Intel-based phones and tablets would be highly compatible.
However, it's reasonable to assume that phone and tablet versions of both Intel and ARM versions of Windows 8 will have interfaces similar to Windows Phone 7's Metro UI, which means applications could or should be written to take advantage of these interface elements. Touch and swipe requires very different elements from point and click.
What we don't know is whether or not regular Windows 8 applications will run on the Intel-based phone and tablet versions. For example, will people who have both a Windows 8 desktop and Windows 8 tablet be required to buy two separate versions of their applications?
Yet another possibility is that those Intel-based mobile devices will be able to run regular Windows 7 and Windows 8 applications, and also be offered Metro-specific versions as optional alternatives.
On the other hand, it's possible that there could be very few versions offered to buyers as a choice. For example, you probably won't be able to buy any of the ARM versions or even the Intel versions slated for mobile devices. You'll buy device, and Windows 8 will already be on it. Consumers looking to upgrade could be offered the choice of only one version, which could install features as requested -- and paid for -- by the user.
The worst-case scenario would be if users were forced to switch back and forth between modes as they use their applications. The best case scenario is that the difference will be hidden from users, who will simply be able to use new and old applications without having to worry about modes.