TLDR Warning, also upcoming content infoz. Read at your own risk.
None. We are currently equal to them in terms of content. There are 2 major content patches for the game, which is Destruction of Beasts, and Queen of Argons, but QoA is in 2 parts. We both currently have DoB and both have QoA part 1, and are both scheduled to get QoA part 2 sometime this summer from what I have heard. The game has been out just a hair over a year there, and has 2 major content patches, so that's decent I'd say. EME is not merely translating, but I don't think they have the power to just totally go in a different direction on their own. But I do think they have the power to have Bluehole implement specific things at their request.
According to this picture, they release a content patch quarterly.
We have most of the stuff up until 2012, and they are about a quarter behind on a few things. According to the pic and other sources, we are still due to get
-Level cap increase
-A new class
-Server vs Server
-Battlegrounds
-20 man raids
-Guild housing
-More guild levels
-Cross server neutral city
-PVP invasions of other servers
-Improved political system
-Floating capital city that can be moved and effects the entire server with buffs/bonuses. Can be parked in SvS area as a drop point for reinforcements.
-Revamped tradeskills
-New armor and weapons models and tier
-PVP Honor like system with purchasable pvp gear
-Ranked battlegrounds? (group matching)
-Warrior and Lancer buffs for tanking
Server invasions & a huge aerial city will be implemented by early next year.
The Demonic Beast of Destruction patch will introduce teamwork, opposition and resistance. If the current TERA is about 5 man PvE parties, for the future it will be about server vs server opposition and large scale battles. BHS mentioned 4 updates that will bring this to life.
The server neutral city of Agaia will open up frequently and will be a place multiple servers will share. This area will provide different kinds of PvE and PvP experiences. Each servers Archons will have to fight off the other servers in order to provide a better experience for their own server players.
Through Agaia, players can also invade other servers, allowing them to collect Dream Shards. To balance out the power, the server matching will change depending on how many shards a server has.
Lastly, early next year, the fourth major city called Juras Ark will be revealed. Juras Ark can only be acquired through politics and the policies made through Juras will be server wide, affecting more than one continent. If Dream Shard and Agaia is about power, Juras is about how to use that power.
For example, if you are in a server that takes great care at PvP and server vs server wars, you can move Juras to the middle of Agaia, to use as a floating fortress. Along with the Juras Ark patch, TERAs ninth class will be revealed.
K-TERA Press Conference: Demon Beast of Destruction - TERA Fans Online Forums
...The 20 man party aka Raid Party will be added.
10vs10 BGs are being actively worked on, also PvP balance is being analyzed. Additionally, monsters will be placed on the maps for a more strategic battle, by defeating the monsters the party will get additional buffs. BG party matching also being worked on. (We also know they are adding other BG's without monsters, such as deathmatch style and Arathi Basin node capture/defense style).
Part 2 of the Argon Queen update will feature major changes for our tankers.
Warriors as tankers proove to be a difficult issue to handle but the second part of Argon Queen update aims to solve these problems. Various balance restoring plans will be tested out.
One of them is the Stamina Bar/Gauge you can see above (I assume the current stamina will revert back to condition as it was referred to previously). If a Lancer successfully blocks an attack no MP will be consumed but Stamina instead. This will ensure that Lancers will have better resources.
Warriors on the other hand will be able to continually evade and dodge attacks while they have Stamina so as long as you have stamina, no cooldown will be applied to the skill.
The formal introduction of the Stamina Gauge is yet to be finalized but the current internal tester's feedback was positive so far.
Warriors will get additional tanking skills and Lancers will get some skills to enhance solo gameplay.
https://forum.tera-europe.com/showthread.php?t=54718
En Masse also trotted out the first mention of its plans for server vs. server combat. The system is designed to provide additional endgame content via PvE and PvP. "It's going to have players from other servers coming to your territory, on your server, and invading your space," Hager explained. He went on to mention how guilds will need to ally with one another to repel the invaders, and if the alliance proves strong enough, take the fight back to the invaders' home turf. En Masse was very coy about the details on this new system, and we expect more information will be forthcoming as we move toward TERA's spring 2012 release date.
PAX 2011: TERA producers reveal server vs. server endgame content | Massively
If they can pull all this shit off and get some raids in there, hoooooly shit, they can have my dollars. Really though, if they can pull this SvS stuff off and whatnot, this game will be king of PvP and have solid PvE. It sounds so much more promising to me than GW2 PvP even.