Clemens Vasters has written a post about how O/R Mapping can't be such a good thing since it hasn't taken over the world. His post is called The sirens are singing: O/R Mapping.
As usual, no one tool is ever the silver bullet. Saying that, I definitely think that there are situations where O/R Mapping is good solution. Clemens was sent a number of fun comments and I can't wait to hear his answers to some of them.
:-)