I just wanted to say that I was lucky enough not to be really stressed at all because of the move--mostly because we'd been super, super super lucky with DH's job so I didn't have to rush to find work. I think it's more like what happens to new teachers, you get sick ALL the time when you first start because you're coming in contact with all sorts of new bugs. I imagine it's a lot like this here--plus, like you say, stressful for a lot of people, so that suppresses the immune system.
Also, phatbeetle, hee! There was one point where DH and I were just cycling through different types of illness. We got colds, bronchitis, the flu, and recently we both broke out in hives. Ahh, the joys of marriage.