Considering it's all new material, an improvement over all their previous albums, and epic as fuck, I'm not sure how this isn't AT LEAST a top 3 contender.
In fact, as I think about it, the only bands to have released their best albums to date are:
Moonsorrow, Rudra, and Nokturnal Mortum (if you forget ToV being released in '04).
Every other band I've heard has a better album elsewhere in their catalog.