Unfortunately, most of the people who are capable of making a PVP server choose not to because of the time and effort it takes to tie in PVP to EverQuest, which is a PVE game (though it is still fun unintentionally to play PVP, I am sure the creative way people play PvP is not the way SOE intended it when they launched a PvP server.)
That being said I do want to make a PvP server... someday. I don't have the motivation or knowledge that much into what a PvP community wants, however I do know how they behave when mechanics are not properly implemented, such as x item is OP compared to y, or something to that degree.
As for the main branch... it's okay for pvp
with a lot of work. Most of the custom ideas people have enjoyed are not in EQEmulator's main branch, mainly because none of them fit in the EQ PvP standard. That being said, if someone were to drastically change combat and balance Player versus Player, it could be the next big thing.
Few things i've learned from my experiments on PvP:
1) Players do like to see new things, as long as they are elaborately implemented. Something like EQ reimagined like Shards of Dalaya almost.
2) Players don't like to have balance issues. This includes one team dominating everyone because they are coordinated and use the OP advantage. This is fixed by adding team-based PvP.
3) PVP should give even the most casual players an advantage even if they don't kill someone. Kills should be part of PvP, but there should be some sort of goal for each team to accomplish otherwise it's EQ Deathmatch.
4) PVP should be mixed in with PVE, but you should never have to PVE to PVP. The only case this would be is something like DAOC keep defense, where you gain ranks for capturing keeps, and ranks for successfully holding off a keep.
5) PVP should be limited to one box only/IP restricted with no exemptions. Have a second one and you open up a ton of possibilities for exploitation, even if it is exempt. I swear some of you use MQ2 scripts to imitate your imaginary wives.
6) Players love to kill dragons. However this shouldn't be the primary goal for everyone. There should be a goal you fight over, not work together on. With the forced team pvp, this works wonders, as you no longer have a choice on whether you can attack an NPC, you either beat the opposing faction or give it to them.
7) Enforcing rules is a lost cause. VZTZ is proof of this. Anything that requires human intervention should be accepted and possibly integrated in some way, shape, or form. An example would be to distribute precompiled MQ2 to your players without the macro part of it, and just the plugin part. Allow only certain plugins to be attached.
On the subject of MQ2... either embrace it or detect it. If you think you can permanently stop it, you are wrong. If you think you can detect it and manually ban people who are using it, you have the right idea and execution. If you choose to embrace it, be prepared to distribute it, or let those who don't have it have a disadvantage.
9) Players hate embracing MQ2, but honestly, forcing role/anon on players is probably a better idea, as is disallowing /who all zone. This allows PVP to happen as soon as you enter a zone and doesn't allow escaping. At the same time, it ruins the element of surprise. Honestly, what's better: The chase, or fighting each other? Most players would fight each other, and by enabling MQ2 Maps on both clients you eliminate people not having MQ2 and being ganked by people that do, and people that do not have MQ2 do not have people run as soon as they get close. If they're gonna run, they're gonna run. No amount of MQ2 usage can stop a death, though
10) Don't make too many zones. Players hate finding PVP, especially on smaller servers.
That's my advice for everyone who wants to make a PVP server. I am sure a lot of the PVP vets will disagree with me on the MQ2 part, but I sincerely believe it's a good idea.