I don't think killing OBL was hollow. I think it did considerable damage to the organization which, combined with a decade of effort by our forces and others, has greatly weakened that particular group. Unfortunately, there are other threats, the world is a dangerous place and things don't get wrapped up by the commercial break.
I didn't clarify -- I certainly believe that finding and executing OBL was a victory for the USA and this has struck a solid blow to Al Queda. However, I was referring to the hollow feeling inside me -- yeah, justice has been served, but it still won't bring me back to how things felt before...