Need the new OneDrive (and SharePoint) Next Generation Sync Client on your computer? Download the bits directly from here:
Update 02. Nov. 2016: Download-Link replaced.
Follow this following link to get the latest version of the NGSC client, since Microsoft is currently updating the client almost daily...
If you have an older version installed, this will be automatically overwritten by the new client.
The NGSC client supports OneDrive for Business and SharePoint Online.
After the installation you see the blue icon in the System Tray. The About should show the latest version 17.3.6673.1011 (which is updated from Microsoft, see link above....)
The cool part is that you can select the folders to synchronize for each site.
Find details about the NGSC SyncClient in Hans Brender's blog.