I understand that it's a solemn occasion for some. People who have been in combat for example will tell you that there is no joy in killing the enemy. The same can be applied here.
That said, Saddam was responsible for the torture and death of many people. Saddam played for keeps and he payed for it. Saddam was captured, tried, convicted, and put to death.
I celebrate that a monster like him has been successfully removed never to hurt anybody again.
I believe that is what most are celebrating. I certainly wouldn't begrudge the celebration. I certainly wouldn't call it ghoulish.
I celebrate it too.
Not yet. There's that little matter of burning in Hell for all eternity, if it is so decided. :-)