Perez - Map the forest trails, but leave the trees. Reduce the CoT influence to the center areas of the park; but increase Vhazilok presence and put them in direct competition with the Hellions and Skulls. Add an abandoned hospital to the zone, and add a low-level taskforce (2-3 missions or so, nothing too strenuous) to "clear" the hospital of Vhazilok presence. Possibly include a fight with the good Doctor himself. The good doctor is probably very interested in the Hydra--so some Hydra Abominations would probably make interesting TF mobs.
Alternatively, you could drop a Shivan meteor into the lake and have Shivan Hydra.
Boomtown - Council vs. 5th Column. Make this place an absolute war zone, with actual Council and 5th column bases, (and the Clockwork King in the north trying to put together a clockwork kingdom--perhaps abducting people so he can have some brain-in-a-jar friends) complete with raids, etc. Let villain PCs visit to help or hinder one side; while heroes clean up the mobs (like siren's call, but PVE only--Villains help one side or the other gain an advantage (and are temporarily allied to either the 5th, council, or the clockwork king), while heroes work with the PPD (Not Longbow!) to try to secure sections of the zone.
Dark Astoria - Make it sepia. Seriously. Add a few stealth mobs here and there, an Arachnos Mu presence, some insane ghosts, etc. Let villains visit, too. The Mu should be hero-attackable, villain friendly--and are secretly working with the Midnighters to end some sort of Banished Pantheon plot. Sneak in a TF for both sides.
Terra Volta - This one's tricky, and I can't see of a way to make it co-op or competitive PVE. Perhaps this'd be a good place for a big red ball? Sky raiders attacking office buildings would be nifty, but I really can't think of anything that'd fit here.
General zone ideas:
Perez - Map the forest trails, but leave the trees. Reduce the CoT influence to the center areas of the park; but increase Vhazilok presence and put them in direct competition with the Hellions and Skulls. Add an abandoned hospital to the zone, and add a low-level taskforce (2-3 missions or so, nothing too strenuous) to "clear" the hospital of Vhazilok presence. Possibly include a fight with the good Doctor himself. The good doctor is probably very interested in the Hydra--so some Hydra Abominations would probably make interesting TF mobs.
Alternatively, you could drop a Shivan meteor into the lake and have Shivan Hydra.
Boomtown - Council vs. 5th Column. Make this place an absolute war zone, with actual Council and 5th column bases, (and the Clockwork King in the north trying to put together a clockwork kingdom--perhaps abducting people so he can have some brain-in-a-jar friends) complete with raids, etc. Let villain PCs visit to help or hinder one side; while heroes clean up the mobs (like siren's call, but PVE only--Villains help one side or the other gain an advantage (and are temporarily allied to either the 5th, council, or the clockwork king), while heroes work with the PPD (Not Longbow!) to try to secure sections of the zone.
Dark Astoria - Make it sepia. Seriously. Add a few stealth mobs here and there, an Arachnos Mu presence, some insane ghosts, etc. Let villains visit, too. The Mu should be hero-attackable, villain friendly--and are secretly working with the Midnighters to end some sort of Banished Pantheon plot. Sneak in a TF for both sides.
Terra Volta - This one's tricky, and I can't see of a way to make it co-op or competitive PVE. Perhaps this'd be a good place for a big red ball? Sky raiders attacking office buildings would be nifty, but I really can't think of anything that'd fit here.