Re; current threads (WOD, Ascians, Warring Triad/is Regula going to be Kefka? etc)... I'm not so sure those will run beyond 3.5x. I can't find the quote at the moment, but didn't Yoshida mention that players would not have to clear through the 2.0/3.0 stories to start 4.0? I'm sure that was their thinking. I therefore can't imagine they will want to carry very many elements over into the 4.0 story. It would be a real slow start to a story if they had to fill in new players in on content they have been able to bypass.

Of all the threads with an easy way in for new players, it's the suspected involvement of Yda and Papalymo with the Ala Mhigan resistance. If, and I stress if at this stage, 4.0 does take us in that direction, then the resistance is a likely vehicle for the player to get involved with. Y+P can either acknowledge the player if they've done 2.0/3.0, or work with them as newbies.

So, prediction time. Ascians, Warriors of Darkness, Hydfillia will all get squared away. We're going to head off from Eorzea, so it would be sensible to finish off those stories. Regula/Kefa goes mad and offs the emperor, leaving a power vacuum in Garlemald and her dominions. With the empire in an uncertain situation, the resistance seizes its moment, and thus enter the Warrior of Light. And new players just need to understand that there's a power vacuum and this is the moment for liberation.