Like Paul said, if you're not highly employable (i.e. in a field or with qualifications that you could fairly easily find a new job), then you should start looking for a new job now.
Maybe you never get laid off, so worst case is that you find out if you are under paid and could come out with a better job! Maybe you are on the firing list, and then you are at least somewhat prepared and are at least in the process somewhat with a few different opportunities.
Not sure where you fit in exactly, but it never hurts to be prepared.