I always enjoy hearing of APUG members who are local to each other getting together to meet and enjoy photography but with active members spread from Australia to Denmark, it sounds as if a worldwide conference would be logistically daunting at best. Add to that the fact that creative folks tend to be, well... rather opinionated, all of the elements a complex event might be beyond the hope of reaching any consensus. (remember the simple "Name the Magazine" thread? There were as many suggestions as members. Poor Aggie finally had to close the thread. )
While it would be an enjoyable event, I have my doubts that it is really feasable.