So, I had a BG idea. Probably far from original at its core, but I haven't seen other people flesh it out much, and often they have unrealistic design expectations that could easily be exploited. I'm a pretty casual PvPer, but I've been doing it since classic, so that's sorta my personal angle. Was thinkin' that maybe I'd post it on the official forums if I got some good feedback, suggestions.
Anyway. Wall of text incoming...
The idea is of a perpetual battleground, something that can't end, where players can jump in to fight their enemies whenever they feel like kicking ass and taking names. There would be no major objectives as a means to "win" and conclude the game. Think of it as some combination between old AV and world pvp. People would queue and drop in and out as they wanted to play and leave when they had their fill.
The theme would be the battlefront. No war games, no flags, no resource control, just the Alliance and Horde gridlocked on the front lines. This wouldn't be a trench warfare style stalemate, though, this would be total chaotic battle. The field of strife at its, uh, strifiest. From a storyline perspective, it's just each faction trying to make a push into enemy territory. From a functional perspective, you're just there to get HKs and your world pvp fix.
Despite a lack of an "end," there would be minor objectives a team could complete. These would be small things; nothing that would allow one faction to get into such a powerful position that the other side could not recover from to continue to enjoy themselves. For example, if your faction pushed past certain predetermined lines or occupied particular territories (determined by numbers, not flag caps), you could get increased honour point gains for X amount of time. There would also be PvP dailies that would encourage active participation in the fighting and supporting your team (rather than just retrieving a banner out of a cave) and reward a small amount of bonus honour and gold. Thematically, it could be paired with a PvE dailies hub "outside" where players did PvE objectives to aide the front lines.
You'd fight amongst filler/support NPCs that would be randomly dispersed within both faction's ranks. They would be weak on damage but have decent health pools. There wouldn't be a lot of them (maybe one for every five PCs) -- it wouldn't feel like a PvE environment -- just enough to inflate the size of the armies. Each side would also have NPCs that repaired and sold food/water (and maybe special bandages). When minor NPCs are killed, they will auto-respawn after X amount of time, although perhaps in random locations.
Looting the fallen enemies (whether NPC or PC) would yield items that you could turn in to earn short term buffs for your team, give you access to items like incapacitating bombs, mines, and turrets for a short time period, or summon stronger NPCs to fight on your side. Corpses would also have a small chance to reward things like rare quality pre-cut pvp gems when looted, or perhaps even have an extremely low chance to get last seasons rings/necks or shoulder enchants. These items would be rewarded by invisible random roll (like how LFR loot is distributed) for players who were involved in their death. Rewards would be desirable but not so good that playing felt mandatory; nothing players couldn't buy with HP directly.
There would be a handful of graveyards around the map and every resurrection cycle the GY your faction will rez at is randomly changed, so you will never rez in a predictable spot, to keep things dynamic and to prevent GY camping. You will only ever rez among your allies.
Honour gains would be tuned to be on par with the "average" typical battleground (not counting dailies), so the choice to participate would be mainly dependent on style preference rather than this battleground being superior for grinding out large amounts of HP. The additional influences for queuing would be dailies and achievements (which allows for further awards if desired).
To help discourage afk-exploitation, players would earn points and access to potential drop rewards only for damaging enemies, healing injured friendlies or doing item turn-ins - no passive/proximity gains. People who go AFK are automatically removed, and players can also flag non-participating players for removal.
To keep it active, make it region wide so there is a very large pool of people to pull from. Give it a hard cap of two or three 40man raid groups, and make the floor is always around ~10 bodies less than the ceiling, so that way you never have a huge faction imbalance (but still has some "give" to speed up queues). You could potentially offer rewards for the underrepresented faction for queuing (like the Call to Arms Adventurer's Satchel) for queuing and playing for X amount of time, although the hope is that with the battle being region-wide faction imbalance would be a non-issue. NPCs could gain a small buff or debuff depending on the amount of PCs on their side in relation to the enemies. Allow players to queue in small groups (10man raid or less) so they can play with friends.
Lots of players are nostalgic for "old AV," lots of players pine for world PvP, lots of players prefer farming HKs in on the roads or midfield rather than completing objectives. This style of game caters to all of them. However, these particular circumstances solve a lot of the issues that influenced "old AV" to evolve into current AV. It provides a place for world PvP without disrupting PvEers. It offers rewards for PvPers that are decent for the time they choose to invest, but not so good that all players feel obligated to participate. It is simple -- just get in there and kill any red names you see -- but can be made more dynamic by utilising turn-ins, but it will never move past its roots of Kill 'Em All.
Would you participate in a game like this?
What weaknesses can you forsee and how would you fix it?
What would you add to build the perfect BG?