What about expired dry dog food?

So I have 40 lbs. of dog food that expired in October 2008. It was stored in a temperature controlled warehouse -- the owner had a pet food store that recently closed. Anyway, I'm wondering if there is any real danger in feeding it to my dog? I'd like to, these days every 40 bucks helps... but I can't do it without at least getting someone else's reasonable thoughts on the matter. I tried searching to find an answer - but none pointed to anything conclusive or were unspecific at best. Help? Thanks... JM