It seems there no inbuilt feature for that. But there is a plugin for that from Nonumber called "Better preview". It also allow to preview unpublished article (not in a new browser tab but in a back-end popup window)

It seems there no inbuilt feature for that. But there is a plugin for that from Nonumber called "Better preview". It also allow to preview unpublished article (not in a new browser tab but in a back-end popup window).

EDIT: its quite buggy on multi-language website (path issue)