Wow, lots of great background info weaving together several of the core 4e gods. I love the story of Gruumsh's invasive merging of his realm with Bane's. It was mentioned in the MotP but delved into more deeply here - two thumbs up!
On the crunch side, those new monsters are nice & fun. Bane's aspects are nasty, and I like how different they both are. An encounter with two of a god's aspects, both with widely differing powers, sounds so cool. Maglubiyet is pure evil too, worthy of his solo status. Any monster that throws PCs at one another wins in my book.
That paragon path is kinda rubbish though.