From the (now defunct) website:
"Promised Sands, as a complete rethinking of the dark, desert fantasy setting, presents rich and detailed new artwork from many artists in the industry. Some are up-and-coming artists whose art can just now be found amongst the newest title releases from other publishers and other art is from fresh faces in the industry who are making a name for themselves with bold and sweeping strokes.
The world of T'nah--the game world for Promised Sands--is a very detailed place. It boasts a rich, 3000+ years of historical development. It is a well-thought out, realistic, widely diverse place full of in-depth and fleshed-out cultures. While the overall feel of the world has a strong Renaissance Arabic influence, there is something for everyone in this world."