Windows 8 is a response to the success of the iPad in particular. Success that has been achieved with no hint of Microsoft Office. Microsoft is late to the tablet game - despite several false starts long before the iPad arrived.
In fact the tablet and phablet markets are growing at such a pace that Windows may shortly be a minority part of the computing market. Restricted to corporate deployments or where legacy applications demand it.
And wither Windows market share leads Office inevitably follows. Which is why Microsoft is looking at different methods of selling Office.
For Microsoft it's not a question of iPad users throwing it all in to switch to Windows 8, rather a question of how it can persuade iPad users that Office is still relevant to them. Those users have found Apple's iWork package to be all they need. Google has similarly delivered Google Docs to Android tablet users with the same results.
Tablets are the new computing platform of choice. Microsoft are late to the party again. They needed Office for tablets two years ago. In another year in won't matter whether it exists or not.
So Bill, time for a rethink. Microsoft needs iPad, not the other way around.