Tabula Rasa is a near-future SciFi game that takes place in a a growing list of worlds, as the Humans are under attack by an alien menace known as The Bane. You play as one of the human resistance fighters.
Tabula Rasa presents an interesting solution to the problem of having to start over with new characters when you want to try a different class. In Tabula Rasa, as you develop your character, you work your way down through a skill tree, each advancement becoming more specific and also more powerful. If you decide at some point that you wish you had tried something different or wish that you had chosen your path differently at some point as you played your game, you can select any point in the progression path of your character and "clone" a new version or "Instance" of that character. In this way, you're not required to start over; you can simply pick up where you left off and try another direction.
In order to give Tabula Rasa a more FPS feel, the UI was designed to be very minimalistic. It shows only what you need to see and, generally, stays out of the way.
In the short time I had to see Tabula Rasa, the A.I. looked to be pretty good. The Bane have their own healer class, Caretakers, which take care of their wounded in the field. Also, when you travel about, you'll not only find Bane NPCs out to get you, but also human resistance soldiers on your side. Also, we're assured that all of the bosses have their own unique tactics.
Richard Garriot explained that they feel that other MMORPG games are not using Instanced areas fully. In Tabula Rasa, the Instanced quests are designed to give the player a single-player feel; the player is supposed to be special - a hero - and these Instanced missions offer an opportunity for the game to show your character to be more than just another soldier in the battlefield. These Instanced areas can be played alone or with your party.
General British continued, saying that with Tabula Rasa they really strove to follow Tolkien's philosophy of creative fiction: you have to create more than just a story to tell, but a larger world composed of the History, Cultures, Science and Philosophy of the creatures in the world. To this end, they have created a symbolic language that is used throughout the game. You learn this language (well, if you're observant) as you play through the game, and the symbols you learn are added to a chart of symbols that you can use later. Reading these symbols allows you to learn secrets of that land - secret technologies and how to use them as you proceed through the game, so keep your eyes open.
At the time of this writing, Tabula Rasa is in live beta with tens of thousands of people.