The new dungeons, trials and the raid look great to me. Main scenario expansion is always good for me (as long as there aren't too many meaningless fetch quests).

Squadrons are basically dead to me because I don't find retainers interesting. I'll use them if they give me nice stuff. Ignore if that isn't the case.

Diadem could be interesting, or it could be a massive failure. 235 gear doesn't sound promising, lol.

The biggest things aside from the actual content, imo, are the Nocturnal Astrologian+Card changes and the Egi Glamours. If the Egi Glamours aren't in the patch, well, that's one less thing I have to look forward to. =|