As an aspiring computer scientist of mediocre credentials, I, evilpaul, shall now tell you, all three of my readers, what Square-Enix will be breaking soon in your immediate FFXI futures.
1) The new ranged attack "efficiency" messages will cause Xbox 360 users to disconnect from the game.
We've seen it before with Aura Steal for great lulz. We'll see it again for ranged attacks. There will be many BG threads about someone on Lakshmi, or another server that I don't think there's actual real life people playing on, who post about Fafnir MPKs because their Aegis PLD was forcibly d/c'd repeatedly until the disreputable HNMLS stole it finally.
2) Ready, the new BST JA, is broken. You can use certain TP moves over and over infinitely until you get bored and do something else. If this includes 1000 Needles it will be used to kill AV and Starcade will Rage Quit over it.
3) Dancer's new Job Trait, "Conserve TP" which is learned at level 40, causes Waltzes to occasionally use less TP activates 100% of the time. Lulz of epic levels ensue as people realize on forums everywhere that Dancers being massively overpowered healers, albeit temporarily, doesn't affect game balance. Square-Enix responds by nerfing Conserve TP to such a degree that stacking equipment with it in every slot is still worthless. So everyone still considers Dancer the 2004 Dragoon of 2009.
4) Evolith NMs spawn claimed to third-parties who were checking the ??? at the time someone else spawned it. It happened with Kirin. It will happen with a mandragora of doom in East Sarutabaruta. And it will be pretty funny.
5) Moblin Maze Mongers fishing things prevents people from getting Fishing skill ups. Thanks to the addition of something involving Fishing with MMM you won't be able to level Fishing.
You heard it here first, folks!
Minor Update: And with the news on POL today, I'm predicting people will cause Spike Flails at Tiamat using field summoned Synergy Furnaces.