For reasons put forward by the devs; to make it more playable at any hour, they removed the darkness at night.
So now, we have a bright daytime and when the clocks reach the hour that is "night", the skybox changes a little and nothing else.
For example, standing in Orgrimmar at night. If you didn't look up and see the skybox is now stars, you wouldn't be able to tell that it's night time at all. The ground is just as bright as the daytime and the shadows cast are from a sun that isn't in the sky.
Nothing kills my immersion more than bad lighting. It's not just bad, it's obvious.
There's been hundreds of threds on this subject, and none have been taken seriously so I put up a petition to bring back the night time. Share the link around, maybe they'll listen.
http://imgur.com/a/ZTv5a - Daytime.
http://imgur.com/a/6TnEv - "Night time"
http://imgur.com/a/7W9XT - Some examples of night as it used to be.
Come on guys, it isn't a night time if the world is just as bright as it is in the day. BRING BACK THE DISTINCTION BETWEEN NIGHT AND DAY!