the 25 minute, script-heavy, year old conceptual tech demo in the OP is what really sold me about this game, although of course i'll have to wait and see exactly how they are going to transform what is demonstrated in the tech demo into a practical game. we already know how certain companies like to pretty up pre-release footage and deliver something else. but this is some seriously amazing presentation from Bungie. i really like the term "MMOFPSRPG", i will probably end up waiting for the PC version if Craptivision bothers with it.
i am wondering how PVP will be done, if there will be such a thing as world PVP or if it will be arena centered. it looks like the storytelling is being cared for.