Yes that CPU is fine for that socket however it depends on what you are using your computer for. That CPU is most likely not suited to your needs and something such as a i5 750 would be better. But obviously I cannot comment on it until you say what you are using it for.
I agree. We need to know what you're going to be using this system for. The problem with the i7 870 is that it's over-priced. If you're looking for an LGA 1156 chip with hyper-threading then I would get the i7 860.