Merit system would be good. Just probably not until 2.3 or later, for realistic application reasons. I'd rather them throw out fully new content/activities to do, before we bust out the old exp grind again. The only reason the Merit System was introduced in XI was to give reason to play after they had exhausted resources at the time. I'd imagine this game would also need to be fine-tuned on the balance portion, as new spells/abilities/stats would mean a lengthy test run of boss fights and theoretical situations for future ones (like avoiding making a merit ability/spell powerful in general, but overly exceeds output due to mechanics of a fight, making this ability/spell "mandatory").