Windows has been the preferred platform for Microsoft applications, especially in the business community. It remains very important. Already released was a version of Office for iPhones however they are leaving money on the table by not bringing their productivity suite to tablets and androids.
SkyDrive, Skype, and OneNote (all by Microsoft) are already available on iOS and Android. We hope they continue in this direction.
Keeping in mind Windows 8 was optimized for tablets, especially the new Surface RT tablets; some speculate Microsoft doesn’t want to hurt the value in their own products. However they should keep in mind the strong trend of people only carrying smartphones and tablets with them in our mobile society. I believe not having Office products available on tablets hurts the Microsoft bottom line.