I don't entirely get why people are so wierded out at the idea of two jobs coming from one class. Given how classes & jobs already work, jobs are just kind of an added tweak to push the class towards a towards a particular party focus. I could see having multiple jobs being kind of like class specs in WoW. Technically those build off the same base, but actually play very differently and often involve using completely different main abilities in party play. Arcanist is supposed to be pet + DoTs, so for example SMN could focus the class more on pet stuff, and SCH could take after the FFXI SCH and emphasize DoT damage. LNC is pretty much already most of the way to being a DRK, and CNJ could easily be pushed towards buffing and/or doing more damage with the "natural" elements as a Geomancer or Green Mage or similar.

Honestly, I was originally a bit tepid on the idea but the more I think about it, the more I hope that's what is actually going on. From a lore/thematic perspective, it fixes some of the weirdness everyone was feeling about the class/job transition, where every adventurer who wielded a spear suddenly developed a burning hate of dragons at level 30. And I suspect that if they do go this route, we'll actually see more jobs overall than we would otherwise since they won't have to spend all of the resources making a full class for each one. Instead of a bunch of people being unhappy upon finding out whether the scout class goes to NIN or THF, wouldn't it be more fun if the answer was both? Wouldn't it make a lot of people happy if they added a RNG job to ARC? The entire idea just seems made of awesome and I don't get why we're angsting about it. :P