Finally! If you are running the latest build of Windows Insider, you can now download the latest preview version of OneDrive sync client. Why?
Finally we can see files or folders that are not synced with the cloud, native in Windows 10! If you install the new preview client, a new column (status) is added in the explorer of Windows. You can see the two icons in above screenshot. The green icon is that the files / folders are synced with my local laptop. The cloud icon is showing the files/folders that are not synced, but they are accessible like a local folder/file, like synced files/folders!
You can enable this via the settings of OneDrive:
Have fun with it!