I really am not sure what niche this book is trying to fill.
If it has rituals and feats and powers and such, that is all player stuff, not NPCs as NPCs run under different rules.
Sure, some players might want to go this route, and more power to them, but what percentage of players is that? I just cannot see this book selling well at all.
It is especially annoying to me (who wants to buy books) that they are selling books that seem to be very niche from the get go, possibly leading to the self-fulfilling prophecy that book sales are dead.
Basically there are four books this year.
1: Heroes of Shadow. For the whitish grey to darkish grey heroes among us, it has vampires, and is a mishmash of essentials and traditional 4E support.
2: Neverwinter campaign Setting. Sure, maybe you can port it out to other places easily (and I am sure it is being built to do that), but it is FR, so a subset CS. Supposedly will have themes and a new class in it, so that might help its sales.
3: Heroes of the Feywild. Don't know anything about this book yet, but will probably be like the HoS, a mishmash of 4E and Essentials stuff, and probably some new races, and a class.
4: BoVD 4E. As said above.
(5) Reworked PHBI classes. I am tempted to call this a book as it (might be) is freely available from DDI, and will cover a bunch of classes, plus having multi-class (maybe even hybrid) rules for 4E and Essentials.
So anemic at best, and each one (IMHO) is a bit niche. Will this support those who want to kill the dead tree format? I think so.