For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
While most Protestant denominations call it "baby dedication", it is not the same ceremony that is described in the Bible, which leads us to the conclusion: This is a man-made tradition.
The bible describes the ritual clearly in Numbers 18 - first born children are dedicated, not all children. Luke 2 describes the sacrifice that must be offered - a pair of pigeons. Obviously, these two instructions are not being followed.