Not many changes in the way of how actual classes/jobs work this time, but outside of that, there's some pretty significant changes.

Long list of stuff being changed and added: http://na.finalfantasyxiv.com/lodestone/topics/detail/69e2c959d2e9285fd541e7f5f70fb8139b3464da

The very top of the New Items list is all the new weapons. Relic weapons in particular look screwy, since this is showing two il100 versions of each. Might these be like the difference between Myth and Coil(1) gear? IE, same basic stats (dmg, def, base), but different secondaries (acc, det, speed)? New Coil(2) gear appears to be all il110, with the weapons being il115. Gonna guess that the other il100 stuff is Soldiery tomes...