I'm using bits from my friend's copy of Frostburn to design a couple of features of the icy north area of my campaign world, which is Norse in flavor. All in all, though, I'm glad I bought the now-defunct Monkey God Enterprises' Frost & Fur instead; F&F actually examines real-world arctic cultures, the Aluet/Inuit/Tlillik, the Norse, and the Slavs, as opposed to the generic fantasy clap-trap in Frostburn. Fluff-wise, Frostburn is a huge disappointment, but they win over F&F in the crunch department, hands down.
Still, feh. Don't really need it, glad I didn't buy it. Waste of 35 bucks if you ask me.