Watched the big reveal yesterday and I am so excited. I have seen several criticisms about it looking very much like Destiny 1. I am ok with this. I love the first game and am fine with Destiny 1.5.
There are still some rumors floating around about cross-platform play, but given the issues people have with putting console players against pc players in FPS, I doubt they would put that in. What I would very much like to see, though, is being able to link my accounts. I have several friends planning on moving over to play on PC and others are staying on PS4. I'd love to be able to just pick which one to play on and have all my stuff available to me. I would buy two copies for that.
New classes. New weapon types. New planets. More Cabal (always felt they were a bit under-represented).