I personally am very excited for this. It seems like they held back a lot of TFS info, which is good in my opinion. We know the basic premise, location, etc., and now I'm pumped to play it. I also appreciate how even though this reveal was disclosed by Joe as being for the widest audience possible, they still include the fact that the final showdown with the Witness is in the raid and not the main campaign. I think they're really pushing raids to a larger audience with that and the LFG system coming in season 23.
Also, all the new weapons are very exciting. Unique subfamilies, support/healing legendaries, Dragon's Breath!. The other returning D1 exotics are super exciting as well. The legendaries are very exciting though; I'm curious how good they'll be and how much they'll shake things up.