Gotta love getting things early! This is why I will never pre-order from GW again -- I've done so in the past and even if the store had my order in the back, they wouldn't give it to me till the official release date. Just another reason why independent FLGSs are awesome and you should support them when you can!
I've only had a few minutes with the book, so an in-depth review will come later, but first impression is this is a big book...
Here it is side by side the new Eldar codex:
So yeah, there's a lot packed in there and from the quick glance of the summary section in the back, I really like what I see so far! I think I'll be dusting off my bike army for this one, and most likely adding more Thunderfire Cannons ;)