If you're a driver, there will be no give back unless you vote on it. No need to worry until your are officially approached by a union rep.
In the mean time, don't give them any ideas.
As far as the hysteria about lay-offs, open the blinds and look out the window. EVERYONE IS LAYING OFF!!! The economy is in the tank right now. You work for a company with very little debt, and a nice size nest egg to get thru this.
As far as jumping ship goes, where the hell do you think you're gonna go get a job, esp in this biz????
Just relax, tighten the belt if needed, and for gods sake don't jump out of the frying pan into the fire.