The statements of design philosophy that underpin this pitch are very troubling to me.  I find the insistence on "verisimilitude" and "historical accuracy" to be more than a little incongruous with the fact that this is a FANTASY setting. 

I also get the feeling that it would be very very difficult for other writers to contribute to this setting productively without trespassing on the originator's desire for 'verisimilitude'.

And while I do think that the pitch includes several neat elements, nothing pops out at me that would keep this from being simply 'yet another fantasy setting' when you came right down to it.  The most I could say is, "yeah, it's a fantasy setting, but trust me it is way more historically accurate that all those other lame fantasy settings."  Historical accuracy isn't really a selling point for a fantasy game.  A novel mix-in, sure, but not enough to make our product stand out on the shelf.

That said, the writing is quite good, and I can tell that the author has put a lot of time and care into his creation.