Between Office 365, tight SkyDrive and SharePoint integration and other features, there's no doubt Office 2013 is aiming for mobile workers. (Still no signs of true iOS or Android versions, though.) Although true mobility is big these days, it's worth asking whether your users are actually all that mobile. A field sales rep might benefit from the anytime, anywhere access; a deskbound CPA might be just fine on Office 2010 or even 2007. Ditto deskbound writers: I'm typing this in a well-loved, full-package-product version of Word 2007.