In my opinion, for each major event, the community should design and vote on one new hunter, ranger, and force weapon (each) for each major event (or another type of item). If that ends up being too much, perhaps just do it once per year. There are so many possibilities.
I had also wondered about creating a higher difficulty with an increased level cap, new items, and increased tech levels. This of course would be expansion-level type of content, but plenty of computer games get modded. Why not PSO? If I were savvy in such an area, I would have been working on this very thing years ago (