Interesting additions to the lore. All of this (except maybe Demi-Princes) have been brought up before in past games or lore. The Slipstream finally gets some detail and it almost seems Mananauts are now.... "canon" to the lore (?) Probably the most interesting part of all this is the idea of "Demi-Princes" though.
http://www.elderscrollsonline.com/en-us/news/post/2015/10/19/loremasters-archive-the-maelstrom-arena---part-one