I played for about a month and half at release and took a hiatus after getting my necro to level 80 and finishing the story. I pretty much had 100% completion on all the Vistas/Hearts/Skill Points minus the three Orr zones and the WvWvW zones.
I updated last night and spent five minutes in Lion's Arch looking for something to do. It was late and I found nothing in regards to NPC's sending me to do something new, so I logged out.
I would really like to sweep up the rest of the map that I missed. I worry that there is nobody doing the Orr stuff, as getting from point A to point B around that place was damned near impossible for me solo. Are the outside zones made up of people from all the servers or just my own?
I remember there being a Halloween event, but I do not recall if any zones opened up since then for exploration.