crazy8-
I've heard a lot of people say that the 7-pot and even some others are hotter than the bhut. The problem is that it's never been proven. NM chile institute grew out the bhut for 4(?) years to get a stable strain and then had it tested for SHU and Guinness was either there or verified the results, giving the bhut the "hottest pepper in the world" classification. None of these other peppers have been followed up on like that.
But I would venture a guess that as the 7-pot gets more ress, something like that will happen.
btw, this is just information I've gathered from online reading so if I've said something incorrect, please feel free to set it straight.