Microsoft isn't making a tablet, nor are they making a tablet-only version of Windows. Aside from the possibility of an ARM version, Windows 8 is the same OS they are developing for servers, desktops and x86 tablets. Even a windows 8 ARM edition will still be based on the same code. By developing an ARM version, they can eliminate the need to code a completely separate mobile OS, like Windows Mobile 7. If Microsoft was concerned about sales of Windows 8 because of an iOS version of Office, they wouldn't make it. Windows 8 will sell regardless. Also, I would have to believe that Microsoft gladly embraces sales of iOS devices because iCloud is running on Microsoft Azure (as well as Amazon). The more iOS devices, the more Apple subscribes to these services, which also happen to run on Microsoft Windows HyperV servers. Basically, every iCloud account is cash in Microsoft's pocket.