Whats this in the Chocobo trailer?

[Endemerrin]

Those are actually Ceruleum Harvesters and/or generators. Ceruleum is the power source for Magitek technology, and it's likely the generators up at the Ceruleum Fields (the name of the area near bluefog) belong to the Garlond Ironworks.

Also, they're a mix of greenish and blueish hues - http://i.imgur.com/tPdF0.jpg


...Secondly, it's most likely a steam / smoke plume as others have stated. Took this screenshot awhile ago - http://i.imgur.com/55Lta.jpg

Obviously not the same location, but it's the same concept.

[Mikita]

Something caught my eye numerous times in the video. At first, I thought it was just an aetheryte, but you can't see aetherytes so far away with this games draw distance, especially one rising to the sky. I'm assuming something will happen with this sometime, but I just found it interesting and thought I'd share.

First Picture @ 21 seconds

Second Picture @ 1:01 seconds

Very observant!

It looks to me like that's coming from the direction of Camp Bluefog.
Not sure what it is or why it's visible, though.

The anticipation builds. ^^