Well they were in a tough spot. On one hand there are a large number of fan boys who crush on the guy. On the other hand he was drunk and punched a co-worker over something stupid.
It will be interesting if the other two guys continue to stand behind him. If they will continue with the show they should rotate the third host betwen a bunch of people and see who sticks. If they just hire someone outright he/she will always be the person that replaced Clarkson to all the crushing fan boys...
Personally I like him and the show but at the same time I think they made the only choice they could have, life goes on. If anyone one of us punched a co-worker like this we would all be gone.