I make an award winning Green Chile Blonde and I add the peppers to the secondary. I actually roast mine on the BBQ, put them in plastic bags, and freeze them. Freezing is supposed to rupture the cell walls and let more of the "goodness" out. I then put the frozen, whole (skins, seeds, etc) pepper in the secondary and rack the beer onto it. Habanero sounds great, and I could be wrong, but won't it "fight" the hops too much in an IPA?