I expected 4.2 to focus on Doma, since 4.1 was nothing but Ala Mhigo. We have two fronts to deal with, and I completely anticipated ping-ponging between the two regions during the reconstruction process. Curious as to who the major players are going to be, since except Tataru the Scions probably can't be too involved given the boat trip. I'm also expecting Gosetsu and [Yo]Tsuyu to make their reappearance here. (What is the actual patch name, by the way?)
Glad to see Azys Lla get more attention; I thought it was the most under-utilized piece of content from Heavensward. I'd have preferred some new piece of the area be explored, such as the Habisphere, but I'll take what I can get. Also nice to see Hells' Lid get explored, though I'm curious as to how it'll distinguish itself from Sohm Al (Hard).
As others have said, basing the new trial series on the Four Symbols from Chinese mythology means that in addition to the White Tiger, we're very likely to get a Blue Dragon, Black Turtle, and Vermilion Bird from 4.3 - 4.5. (The names for these bosses will likely be Byakko, Seiryu, Genbu, and Suzaku, unless they go with the original Chinese names that I don't know and probably couldn't remember the spelling of anyway.)
Eureka is FINALLY here! At last, something for casul players like myself to do besides grind tomestones and run Rabanastre once a week! (I'm maxed on Kojin rep, have capped tomestones in both values, and just need like 2 more Rabanastre clears to max out my gear without raiding.)