I had read somewhere that if a flight has too much checked luggage or the weight of the checked luggage is too much, that the airline will pull the heaviest luggage and send it on a different flight.

Now that we have to check all luggage (I fly next Friday ... 8/18), I am worried about my luggage getting lost. Does anyone know if the airlines give special treatment to the luggage of the passengers flying first or economy (business class) than they do to the rest of us? Will they pull the non-first/economy class luggage off first?

I'm not saying yes or no but when I've upgraded to business or first, my bags are always tagged with a special, brightly colored "PRIORITY" tag and on international flights they are always among the first to come off the conveyor.

That's a very good point, and you're probably spot on. Economy will more than likely be the first to go.