Office 365 is less expensive than any stand alone version of Office, by far. Business users are already going for it. I'm supporting an Office 365 migration on iPhones right now that involves pushing AirWatch Office 365 profiles to the iPhones for e-mail, contacts, and Calendar. It doesn't involve Office, but since the users are already logging into to Office 365 on their jobs, they should be able to login on their Corporate iPads with no expense paid accept for whatever the iPad Office app costs. Don't expect iPad users who already have (or will get) Office 365 subscriptions to just swap those iPads out for Surface Tablets. There's no advantage to doing so, now that Office 365 is available on the iPad. So this strategy will most certainly cannibalize Surface Tablet sales, while Office 365 Corporate subscriptions rise. Home users? That's anyone's guess. This could spur them on to buy an Office 365 subscription, provided they're willing to forgo their still working/stand alone Office version. I personally have no intention of going with the MS Subscription model, as Office for Mac and Office 2003 on my PC work just fine.