The idea is not factions vs faction, it is group vs group. Any 10, 15, 25, or 40 people in a group vs any 10, 15, 25, or 40 people in the other group.
Battleground: Gates of Hell
Your group appears in a room something like the room in Naxx where Gothik is. One side is your group, the other side is the other group.
Every 5 seconds a mob spawns on each side. That's it. The entire fight is a new mob spawning on each side every five seconds.
But wait, that is not really going to be a problem. You are right. So whenever you kill one on your side it appears on the other side. Whenever they kill one it appears on your side.
This means 5 seconds into the fight there will be 2 adds total, 50 seconds into the fight there will be 20 adds total, 1 minute 40 seconds into it there will be 40 adds, 2 and a half minutes there will be 60 adds, you get the idea, no matter how good each side is, they will get overwhelmed.
The adds never die, when they get killed they move to the other side. The group that does better controlling their side will also be doing better making life hell on the other side. When you die however, you get to watch as your team mates try to survive the onslaught by themselves. No battle resurrections allowed here, dead is dead.
As soon as one team is killed off completely the other team wins.
Battleground: Storming the Castle
Both teams zone in on identical maps and make a charge for the castle. You will run up a snow covered map passing 5 check points that you need to decide if they are worth securing or passing. If you secure a check point and someone dies they are resurrected at the closest check point to the group progress. If you do not secure a check point then they spawn all the way back at the beginning.
This will be a long trek and having them catch up might be the difference between victory and defeat. A small map on the right side will show you the other team, their secured check points and their progress up the hill toward the castle.
Waves of soldiers spawn at the top and work their way down the hill, these are the people you need to fight on the way up. Each check point has 20 additional troops that will stay there and only fight at the check point. If you just walk past the point they will not attack.
This would be a 40 man battleground based on the sheer number of mobs you will be facing. Once you get to the castle gates and destroy the three transporters outside of the gates, mobs will stop spawning for the gauntlet you fought on the way up.
There will be two men manning cannons shooting at your group while it is at the gates. They are slow fire but do huge damage and can be avoided from players smart enough to notice their targeting patterns. The gates will have 6 locks on it that will need to be broken down. The two cannons can not be targeted or destroyed. You will need to break the 6 locks while avoiding the huge AoE the shots make.
Once the gates are down the cannons will stop and you will enter a courtyard with 100 mobs of varying classes. You can try to down them all, you can try to rush through them to enter the castle and kill the king with them tagging along. It is up to you. Perhaps the best idea would be to split up here. Perhaps the best idea would be to down them so you have full force on the king. Perhaps the best idea is to just go for the king on a suicide mission knowing the ones from behind will kill you and hoping you kill the king before all of you are killed. Maybe looking at the mini map and seeing where the other team is right now will help you make your decision.
Either way, the first team to kill the king wins the castle, and the match.
Both teams are placed in a room with a mob that will be unbeatable. With over 10 trillion life and regenerating 1% of its life every 5 seconds this creature will be impossible to take down. I guess it is a good thing you do not need to kill it.
Each team will have 2000 points on entry and it will be an effort in perfect performance. I would want every raider on my raid team to do this battleground every chance they get to hone their skills.
The mob will cast spells constantly and unlike most mobs it will continue to melee while casting. Each spell will do different things. Lines of fire. Fire balls. You know, all types of avoidable stuff. Each time someone does not avoid something the team loses 25 points. Meaning if 6 people get hit by something that was avoidable you are now down to 1850.
There will be lots of unavoidable damage to keep the healers working. There will be DPS requirements to break shields that the mob will put on itself that will explode if not taken down in a certain time, causing more point loss if it explodes, and more healer work which could mean deaths, which in turn mean more point loss. It will need tanks that have their taunt rotation down perfectly because if they get hit with the debuff that is 100 points down the drain. If the mob directly hit anyone that is not one of the predetermined tanks it will one shot them meaning a loss of points for a death and a loss of points for a non tank being hit by a melee hit. Don't forget the cleave either, melee getting hit by that will lose them points too.
Everyone will need to do what they are supposed to do. The perfect training for raiders that are new or even older ones that want to brag about their ability to avoid the avoidable, which some people seem to have major issues with. I am sure having the achievement [Monstrosity Perfection - 2000 Points] will be something people would love to brag about.
First team to run out of points losses. The other team gets the win for basically doing their job better. Two fantastic teams will start to run down to who runs out of mana first. No matter how great you are, this fight will come to and end with one team at 0 one way or another.
These are just a few of the ideas I had for some PvE battlegrounds. I think it would be a cool addition to the game and it surely would be a lot nicer to add additional options to getting VP.
Not to mention, for those guilds that are not really into PvP it gives them a way to get some rated battlegrounds achievements as these would indeed be battlegrounds and you could make premades.
I think it would be kind of fun to get a guild premade all set up and grind your weekly valor this way instead of doing dungeons that are basically outdated gear wise. Once your dungeon gear grind is done this will give people options outside of raiding or doing outdated content for their VP.
Even VP aside, having something else to do in game is always a good thing. Don't you think?
I do think that some sort of additional "reward" would be needed for some people to be interested. Perhaps additional PvE gear that can be purchased with valor points but only after a certain amount of PvE battleground wins to unlock it.
Personally I think making all the 378 BoE things available for valor after 30 wins would be a good idea. However, they would no longer be BoE, if purchased from that vendor it would be BoP. To keep people from farming BoEs with battlegrounds. Maybe another "reward" might be better, that is just one idea.
The concept of PvE battleground as a whole I think is a good idea. Something new and different and a direct challenge of PvE vs PvE. I'm all for anything that gives us other things to do.