These are Eldar and Dark Eldar in this trailer. What everyone fails to see in this thread so far is that these Eldar are Corsair Eldar. The most arrogant and wild spirited of all Eldar. They do not follow the patch. they live life to their hearths content and the trill of combat, adventure and the exploring the edges of the galaxy. They answer to no one, only on very rare favour/contracts of important Farseers, Archons and Autarchs (maybe and Exodite world). These are the Eldar that bump into Rogue traders and random planets and mess things up because they can. They have no care in the world, they are all outcasts. It is because of these Eldar that the Universe sees them as arrogant to the Max race that they are. The Battle Fleet Gothic lore is cool, give it a shot (not only for Eldar, but all the other races). It Also shows you it is not easy to make a Eldar Craftworld Army with Eldar Corsairs and or Dark Eldar.
Pretty good by my standards. The taunt at the end was...GLORIOUS! I cant wait to shell them with thrice-blessed macro-canons. If I can see or catch them that is. In either case...Omnissiah will provide.