The NDA given to the press at PAX has lifted, and previews are popping up on major gaming sites everywhere.
Some of the more important (imo) points:
There will be a pretty clear distinction between PvE and PvP; the first will take place in the 'real world', where the factions are more concerned with rooting out evil. The second will take place in Agrathea, the Hollow Earth, and this is where cabals (guilds) will be fighting to control areas providing resources for crafting and advantages in the world above. Upon entering Agrathea, your character will apparently don your faction's uniform automatically, so enemies are easily identifiable.
Character progression is horizontal rather than vertical. In other words, there are no levels. Instead you will gain new skills (it seems you can only have a few active) allowing you to specialize or hybridize more in a way you prefer. A new player will stand a decent chance against an experienced player, and an experienced player on a new character should be able to own a noob on an ebayed character through superior skill. There will be no restrictions on what abilities and items you can use through factions, apart from faction-specific quest rewards. This means faction balance shouldn't be a problem, only ability balance.
Combat apparently uses a targeting reticle, and ability cooldowns will be short.
There will be rankings for all kinds of things online, like kills, crafting ability and questing. There will be titles etc, which will apparently be integrated with services like Twitter.
It is a design intent that this games isn't like WoW. TSW will be more of a game you pick up for an hour, possibly in addition to another MMO.
All in all, this new info has me quite exited. I'm hoping I make it into beta, when that happens. I'm not quite sure what faction I'd want to play; I expect that will depend on which one the people I want to play with will choose. It seems Dragon is by far the most-occuring result in the online personality test, which may be because they're the asian faction with the cool katanas etc. (which all factions will be able to use, as far as I know).
Quick edit:
Some more stuff; clothing will not affect your stats, so you can choose your appearence without having to worry about that. An important way to progress in the game will be through your standing with your faction, and your cabal's standing with it. Cabals will have housing which can be improved as the cabal gets higher in rank. You will be able to enter the enemy headquarters and do annoying stuff there, but you'll be attacked on sight.