This update will bring extra document management capabilities from SharePoint into Microsoft Teams.
The current Microsoft Teams files experience
The document storage and collaboration functionality in Microsoft Teams is built on SharePoint. Every Microsoft Team is also an Office 365 Group, and each team has a group-connected SharePoint site which stores all the files shared amongst the team.
You can already reach this site from the files tab of your Microsoft Teams channels, however the experience within Teams is a bit limited.
An updated Document Library experience in Microsoft Teams
This update brings the full functionality of a SharePoint Document Library into Microsoft Teams. With the ability to add and manage custom columns, sort and filter files with custom views, trigger workflows and much more.
Sync files from Microsoft Teams with your PC or Mac
This is the standout feature in this update. The ability to sync files with a PC or Mac will be available from within Microsoft teams. At Ignite this year, Microsoft demonstrated the new interface during the Content Collaboration in the Modern Workplace – BRK2451 session.
This screen capture demonstrates custom columns, views and formatting, as well as the new sync button within Microsoft Teams.
The roadmap update for this feature listed a general availability date of Q3 of calendar year 2018, so it should be rolling out any minute now.
For more info on this feature, see the Content Collaboration in the Modern Workplace session from Microsoft Ignite.