Since you guys don't want to have seperate server for PvE because of the logistics nightmare of having another realm, and character transfer and such, I propose an alternative. A Custom NPC found in Stormwind and Orgrimmar respectively that for a price of 1 gold you can switch your server preference from PvP to PvE, or vise versa, with a 24 hour cooldown on the effect. You wouldn't need a new server, and it would consist of adding two custom NPCs and maybe a few custom debuffs and PvP and PvE realm preference.
I know you guys want to stick with being as blizzlike as possible, but let me tell you, not having a PvE realm alongside and PvP realm is not blizzlike because in the old days there where many realms. So by refusing to have another realm for PvE your are diverging from your desired "blizzlike" design. What is 1 other divergence to give people the option to opt out of the world pvp aspect of a PvP server?
You can use this addition to also gather data to determine what the community thinks concerning a PvP realm and PvE realm rather than based on the word of a few. As a leveling player I hate world PvP because its almost never me being the aggressor its horde attacking me. Don't believe? go to STV and look at all the skeletons at Nesingway's camp, read the general chat and you'll see at nearly all times of day the horde endlessly camp STV. I hate ganking because its only slowing me down, preventing me from accomplishing what I want. If I want PvP that is what battlegrounds are for or Gurubashi Arena.