As of the missions update, you can remotely enter the Clockworks via the Missions panel. You used to only be able to do this via the Arcade. Now, I hardly see ANYONE in the Arcade at all, because they dont really have any reason to go in there. The Arcade nowadays only has 2 real uses:
1. Mineral Deposit, which as of the Battle Sprite update, isnt going to be used that much anymore (Not that it was in the first place.).
2. Sullivan, who sells all those OP PvP weapons and trinkets.
So really, the only reason to go in there is for Sullivan. Which means that the Arcade is almost useless.

Here are my ideas:
1. Remove the Arcade tab from the Missions panel. This will give people a reason to go into the Arcade, for they have to go into the Clockworks that way.
2. Put some new NPCs or something in there. The only NPCs in the Arcade are tutorial NPCs (Sullivan excluded), so many players will only be in there once or twice, and then never see it again.
3. Host events in the Arcade. Impostoclaus showing up next to Sullivan to say 3 sentences of dialouge isnt much of an event. Host events like clockwork races, announcements, or just getting to see the Game Masters other than when your stuck in the clockworks. Anything.
4. Put in more shops than just a PvP vendor. I know that there is a bazaar for this type of thing, but its mostly just Stranger vendors. Put in another vendor, like one that sells stuff you wouldnt usually see (NOT TALKING ABOUT BRINKS OR KOZMA)
5. Have that Roarmulus fight in the arcade. The purpouse of the Roarmulus Twins were to bring up through the arcade to attack haven. I would love to fight those things there. :)
6. Put the actual PvP lobby in the arcade, or a signup post. Gives people a reason to go in there, because I know how much people LOVE to do PvP. (Thank you Coelydragon.)

Just some ideas.