I always felt that there was a very big difference between hula and bellydance. Hula is a story told with the hands and the dancers use (mostly) their feet to produce the moves, aside from a few things like mayas. Since the point of hula is to tell a story with the hands removing that element seems like it's just a bellydancer in a grass skirt to me.
Here is some Hawaiian hula at the Merrie Monarch festival; see if you can spot the difference between the two forms of dance (by which I mean bellydance and hula):
YouTube - Merrie Monarch 2006
YouTube - Halau Mohala `Ilima (Auana Wahine) Merrie Monarch 2007