I don't really understand what the difference is between Jobs and Class. I have always thought they were the same thing, just called differently by people.
Imagine Lancer 30 opens 3 quests. One of the quests gives you the job Dragoon. The two others Halbardier and Pikemen.
Your lancer is still rank 50, and you still have most of the moves that you currently know in FFXIV, except the few that have been changed and redesigned. For the most part and for solo-play, nothing really changed.
Now, for example, you join a party. They already have a lancer, so you pick the job Dragoon (a damage-dealing specialist variation of the lancer), which grants you the Jump Ability, but you lose the Surges.
The other lancer picks Halbardier (a defensive/control-based specialist), who gives him stronger surges and more control abilities (bind, trammel, etc.)
If one of you had picked Pikemen (A big-hitter that specializes in helping the tank with threat), you would have gained increased damage with doomspike, but lost the ability to feint.
Those are just examples, but it's the impression I get in a nutshell.
Many people also have concerns about threat and making it too easy on tanks. For example:
why shouldn't tanks know how much enmity they're generating to keep hate on themselves?
Actually, the description in the blueprint says that it shows how much threat you have compared to whoever the creature is attacking.
This means that as the tank, all you'll see is usually 100%. (or below 100% when you lose agro)
If you play a DPS, and you see 90%, you know you'll steal agro soon, and you have to hold back (or go ahead and start tanking). As a tank, however, you should not be able to how much threat everyone has from this change. In WoW's default UI, they put a yellow glow over players who are about to steal agro from you, and in red those who are actually the target of a mob. That would make tanking "easier" (or more predictable), but the current design does not specify if they'll copy that feature too.
It's a useful tool for damage dealers and healers to thread the hateline, but it doesn't help tanks know how far ahead they are from their team. Tanking remains "difficult" (and even if you had a million threat really, a good tank will always want MOAR -- no good reason to start slacking just because you have some lead. Turtle and the hare, anyone?) Edited, May 19th 2011 1:05pm by Docent42 Edited, May 19th 2011 1:06pm by Docent42