I do think it's a significant event, but not because of the unfortunate deaths. It's a significant event because it's a message from the French government that is telling America to watch what it does. The fact of the matter is, the French have satellite technology capable of scrambling signals aboard American space craft. The French deliberately did this to Columbia, which resulted in erroneus calculations in the decent -- thereby increasing the velocity (and therefore heat). This is also the reason communinaction was lost "almost like a wire was cut".
Why would the French do this? In retaliation for the French 747 that was shot down by Amreican Submarines during the Clinton Administration. That 747 was full of French intelligence operatives and America (ie. Clinton) didn't want French getting ahold of their secrets. Boeing came up with some idiotic reason for the crash, and America got away with one. Of course the French knew about it, and the result is this challenger disaster, which was supposedly caused by two missing tiles. That's of course a load of crap, because shuttles have come down with missing tiles in the past. French is also quite opposed to the war on Iraq, so I'm sure that had something to do with it.
Then again, maybe I've listened to one too many conspiracy radio shows. In that case, I return to my "that's unfortunate, but who really cares" arguement.