Microsoft provides details on future of Office for Mac and iOS - Macworld Australia

Perhaps the new Office Web Apps are Microsoft's strategic plan for Mac OS, iPad, and Android tablet devices as well

"But what does this mean for the future of Office for Mac and iOS users? Macworld has learned that when the new Office launches, Microsoft will deliver an update to Office for Mac 2011. With this update, Office for Mac licenses can count as part of an Office 365 Home Premium subscription, making it possible to access your Office documents in the cloud.
Those using iOS devices will also have access to these online applications. Office Mobile will work with Windows Phones, Android phones and iOS devices. Details weren’t forthcoming on Monday, but Microsoft will likely have more to say about Office Mobile within the next year. The company had no comment on when we might expect a Mac equivalent of Office 2013."

Microsoft provides details on future of Office for Mac and iOS - Macworld Australia