Artoomis said:
I don't think so. I think that attacking unarmed is the reason there is an AoO. I infer that from:
Unfortunately, that is far from clear. Does Improved Unarmed negate the AoO from making a trip attempt as well as the AoO from striking unarmed? The only way I could say that for sure would be if the description of IUS included the "tripping weapon" phrasing.