Inspect them, clean them if you want, repack and stick em back. I have never ever had a wheel bearing fail on my Volvos or any car I ever owned for that matter and I have been driving for quite a few years. I too believe in the "if it aint broke don't fix it" philosophy for certain things and wheel bearing are one of them. They will typically last the life of the car and beyond and still be in perfect shape. All of the above assumes they are kept adjusted correctly. Another reason not to change is that they will always give plenty of warning of impending failure so you won't get stranded.