If there HAS to be a merge, I'd vote for separate pvp enabled vs nonpvp enabled zones for all areas, just like the epic vs normal now. And it would be better to have a global: pvp chat channel so hopefully the trash talking sewer spewing pvp badmouthing trolls could have their own channel. Most of the trash talk that I see in global now is directly related to pvp: you can't tell me that it won't get worse if all servers were merged. I was there for the Cimmeria/Tyranny merge: when world pvp became gankathons and killing someone fighting npcs became 'normal par for the course'. And when Tyranny became Fury. I saw what the average global comments turned into. Even wiccana going to Crom brought more verbal diarrhea in global when the Fury pvpers moved over to get more action/victims in minis and such.
Its not just the concerns on world pvp, its the pvp mindset of a few in global that I'm not looking forward to the most.