Box announces new level of integration with Office 365, and drops storage limits on Dropbox Business tier

Box, the file sync-and-share player, made two announcements yesterday.
The first is Box falling into line with other vendors that have been dropping storage limits for business accounts. Box offered an Enterprise tier of pricing since 2011 — $35/user/month — that has unlimited storage. But not the Business tier — formerly limited to 1000 GB — is now unlimited for $15/user/month.
I’ve been tracking the free fall in file sync-and-store, as the cost of storing files is falling to zero. Recent events:

Things are changing at a blinding speed in this sector, and Box’s rapid accommodation of unlimited files as table stakes is an indicator of that new reality.
The second announcement was about the company’s relationship with Microsoft. In particular, Office 365 users can open, edit, share, and save files from Box in Office apps: Powerpoint, Excel, and Word. Also, users of Outlook can now share links to files in Box in Outlook email, and convert attachments to Box shared links.
I wonder how far this relationship with Microsoft will go? Or is it just a way to counter the weakness in Box’s product offering? While Box does have its own Box Notes app, that is no substitute for Office, Google Docs, or Apple’s suite of productivity tools.