If you're on the edge about shelling $ 9.95 a month to play Hellgate London's premium mode, Flagship finally posted a more substantial list of what you'd be getting. Most of the stuff is rubbish, but they finally went out on a limb stating that subscribers will in fact get additional playable content. TONS of it! (ahem):

We’re always making TONS of new content for our subscribers that extends and changes the way Hellgate: London can be played.

This includes:

New Levels to Explore
New Monsters
New Weapons
New Skills and Spells
New Quests and Storyline
New Character Classes

Themed Events and Items

These are events, areas, monsters, quests, pets and rewards that are available for limited periods of time throughout the year. Some are recurring while others may only happen once, so keep a sharp watch for announcements on upcoming events!

Hardcore Mode

Characters have one life, and ONLY one life, to give for the cause. There is no resurrecting your downed hero in Hardcore mode, so different tactics, skills and items rule the day. For the gamer that wants the ultimate test, try playing an Elite Hardcore character!

Guild Creation and Management

By purchasing a Guild Herald, a character can form a new guild. Characters can only be part of one guild at a time and should a Guild leader decide to abandon their post, they can pass leadership of the Guild to another subscribing guild member.

Achievement Rewards

You’re earning big points for completing long-term goals and insane tasks. Along with the notoriety and sense of accomplishment, there are also rewards to spend those points on!

PvP Modes and Rewards

New ways to fight against other players, both alone and in teams. Your reputation in this arena of combat will also net you special commendations and rewards!

Larger Stash

Each character gets an extra 6x8 section in their storage locker, making the hording of all sorts of goodies that much easier. Pack rats rejoice!

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