Are Sperm Donors Really Anonymous Anymore?

Today MSN featured a Slate article titled Are Sperm Donors Really Anonymous Anymore?  I found it really interesting the way DNA testing and common genealogical research techniques combined to track down an anonymous sperm donor.  I can't imagine missing half of my family tree, wondering where my roots were and who half of my biological relatives are, but I have a relative who came into the world this way.  Would you try to track down your sperm donor father, too?