I'm pretty much with you on that. I look at it more from the view that taking him out hardly puts a stop to the organization. The leader is dead, but someone else will just take his place and now they have even more reason/justification/etc for being all kinds of pissed of at the US. It's really not a time for celebration. The other side of it is so much of the cheering seems to be for revenge, not justice and that's a little disturbing.
Honestly, we're all deranged to some extent. People rejoice in the killing of that which they fear; the problem is that they don't understand how things work, so they fear the wrong things. Bin Laden is like a scapegoatan Azazael that we can send off into the wilderness with all our sins on its back, in hope of peace. Nobody is thinking about how his mother feels about this (if she is still alive).
The trick as practitioners is not simply to notice how others are deranged, and criticize them for it, because generally they don't listen. The real potential in seeing this is to use it as a tool to look within our own hearts to see where our derangement lies, and to try to use the opportunity to break free of it.