I would say a Msoft announcement would be later if at all this...

I would say a Msoft announcement would be later if at all this month, the launch will just be a simple the app is now live on the store and probably reiterate the features and revenue model, targeted users, and perhaps some images or photos of an office launch party.

In following weeks expect to hear announcement about marketing strategy, user downloads, stability of the app, possible glimpse into how the API revenue model is going, or further partners (although the 2nd from last I expect they will hold back for when the share price starts to settle or end of FY, near to the international release to hype it further).