The Hellgate: London Website has word that the end of this month is the deadline to purchase their Founder's offer, which includes all subscriber-content for Flagship's action/RPG, those interested must sign up by January 31. The site includes an additional note that while their recent post about the upcoming Stonehenge expansion focused on subscriber content in the update (story), the update includes non-subscriber content, as well:

Howdy folks! It seems there's a little confusion out there regarding the upcoming patch. Just to make it clear to everyone, there's a lot of stuff in there for both subscribers and non-subscribers. Skill tweaks, UI improvements, respecs, the PvP arena, new animations, and more - these are for everyone.

If you check the patch notes here, everything above "Special Subscriber Features" is included for all players. ^_^

As we continue to expand the Hellgate universe in the coming months, we have every intention to improve the game for everyone, subscriber or not.