I think class would be like a subjob from now on. For example, being a gladiator; it's often handy to have cure spells from con and thm to keep yourself alive, but when you switch to paladin, you will lose all those cure spells from thm and con, and you can now start learning cure spells exclusive to paladin, while still keeping all your gladiator skills. You'd get the benefit of a much higher defense as paladin, which is better for party situations, and those that stick with being a gladiator can become more of a balanced damage dealer type with hybrid skills from all other classes.
I think they are gonna do away with physical level points in exchange for merit point like system from ffxi. Like you can put more points on heavy stab to make it stronger and such.