Nvidia said they would give it away for free for 1080/1080ti users iirc. So if you have that card, you have a game for free. (Let's wait for their feedback.)
No. I've seen nothing showing genuine new content in the form of new assets just many recycled assets and slightly edited assets. Let's also not forget that Destiny has only sort of become the game it was supposed to be now you can get all of the expansions and DLCs as one package.