As Monte stated, this is the project he just could not refuse.
Having most Monte products, especially Chaositech and Ptolus and knwoing he did CoC d20 I know that he loves Lovecraftian Horrors.
I know too that h likes to fiddle with the Core D&D rules and always tries to improve them or opne new optione for GMs and Players (his Arcana Evolved is a good example).
Rurthermore Sean K. Reynolds states that he was responsible for some of the mechanics (one of the former posters had a link).
Monte and SKR did Ghostwalk for WoC. Ghostwalk is a campaign setting where you can play a Ghost.
The Inconnu from the description WW gave out at GTS have many similarities with the Galchutt from Ptolus/Chaoitech which where derived by Monte from Lovecraftian "Gods".
I do not believe that Monte had to fit this project into the WoD Canon. I think he mentioned somewhere that he could almost do as he liked with this setting.
I do believe that this product will not be compatible with WoD. Sure it takes the idea of Vampires and other Monsters roaming through the streets but I do not think that we will see Brujah (or however the Vampire Clans are called in WoD today). I believe we will see a very dark setting. After all Monte also did Book of Vile Darkness.
I believe thate Monte bent the d20 rules to fit his needs for the setting. He is very outspoken about the Vancian mechanics for spellcasters. Soe he will probably invent something new. Maybe along the lines of Arcana Evolved. But it is also likely that he will design something along
this line. As this book has 300+ pages and has to contain the complete setting, I believe the other mechanics will be all about giving the Players a lot of choices to built their Character. It will also strive to give the DM mor options. After all, why should Monte take a step back from his belief how games should b designed?
I think that this will be a product will surprise us with the mechanics.
That said I will surely but the book as soon as it is available.