with only NM, ifrit, NM and DH is not enough....you can call it "end game" but it is very dull, and this thread is make at the wrong time as well, rather wait until SE announcement add content for lvl 50 then you can ask for thing like:

Open dungeon with NM & item hunting.
More dungeon instance (1 is simply not enough, you will be bored of it soon just admit it)
Massive battle : defense a fortress against Beast-man attack/Attack Beast-man's fortress (prefer mobs with ?? stat and hardcore and 1-2 time/week with player choose to have reward as gil or GC seal) * 1-2 time/week will let it laster longer and the LS can organize party and can make it as ls event

those stuff above should be save until SE say they ll begin focus about end game content, and not now when they try to fix the root base of the game

ninja edit: "hardcore" in the Beast-man mean hard mobs dont try to misunderstand the term