What they said back when it was being discussed at HW's launch is that for 4.0 they would probably allow people to start the 4.0 content without having to go through all the HW patch content and such. Instead they would have to create some kind of 'the story so far' so people starting the 4.0 story without going trough all 3.X will know what is going on.

That said, they aren't going to let people just jump straight to lvl 60. Your still going to have to level up a Job to 60 and get enough gear that you don't get oneshot the moment you step into the new zones. Being able to get to the new zones and having the required lvl and gear are two entirely different things.

That said, the lack of bots and such in the HW zones is a very nice bonus of the system.