I do not understand why Blizzard is pushing WPVP in WoD. WPVP only became an issue in MOP when they made PVP gear complete trash in open world content.
How exactly is WPVP going to work well in WoD?
The PVP servers are largely lopsided, which means one faction severely out numbers the other.
It just becomes lambs to the slaughter. It does not matter how good you are at PVP or how good your gear is when 80% to 95% of all players on your realm are enemies. You are just going to end up with the smaller faction buying more realm transfers. I guess that is good for Blizzard.
Successful WPVP takes a good in-game transportation system.
You need to be able to port all over the map as battles pop up at different places. WOW has one of the worst in-game transportation systems in the industry and that is with flying. Currently, if your friend is half a map away, and calls for help, it still takes significant time to get there. By the time help arrives the fighting is done. To make it worse, the removal of flight will completely kill WPVP, as it will be near impossible for guild members to come to a friends help that is in a different area.
Can the server handle large groups of people in concentrated areas?
People talk about how fun the Tarrin Mill/Southshore battles used to be in Vanilla. What no one mentions is how bad the lag was. It was really bad when everyone actually started fighting. I had a good computer with a good internet connection at the time and i used to get super lagged for those battles.
Possible solutions
Allow players to port to party members or raid members with a single click. This works well for Wildstar, Rift and others.
Get rid of Flight paths and make them all portals.
Allow for a secondary grouping mechanism like a guild for just your core PVP group. If you have a large group of people you pvp with who belong to different guilds, there should be an in-game way to send a message to everyone of them. I like how GW2 allows you to belong to multiple guilds at one time.
Allow for Horde to switch to Alliance and vice versa. Every war has traitors.
Allow for a third faction, an anti-faction. I would love to belong to the faction-less and battle both Alliance and Horde.
Develop WPVP survival servers that only allow balanced population growth.
I played Ultima Online since the beginning. Most of my entire time for years in that game was just WPVP. The ability to port around the game through portals and runes allowed for battles to last for hours, even days. It would be nice to play in an environment like that again.