XI gets updates every damn month now. Part of the reason I stopped logging is was because I felt I was getting further and further behind in content, not catching up.
I think the initial content for the expansion will probably include:
- New outerworld zones, some gated behind content
- Several new dungeons to accomodate the new 60 cap
- Big chunk of initial story explaining how you gain access to the new areas, plot set up, etc
- The new jobs (each of which could be like the "advanced" jobs in FFXI where you have to have something at at least 30 to unlock, since there is no base class)
- All new gear, all new crafting recipes, all new levequests, etc
I would bet a dollar that the flying mount won't be accessible right off the bat. It'll have to be something you earn access to through the story, and using it, you can get to the aforementioned gated areas.