First of all, I will say I am biased since I am a pathology resident. A pathology survey course that includes both anatomic and clinical pathology would be a great rotation for students going into all specialties, while a surgical pathology elective +/- autopsy would be great for any one going into surgery or a surgical subspecialty.
Most clinicians have no idea what goes in pathology and why it takes "so long" to get a surgical pathology or frozen section report. Most clinicians have no idea what should really be written as cause of death on death certificates. They don't understand appropriate use of blood products or why it's crucial that we receive patient history with biopsies and other specimens. A pathology elective would also be a great review of diseases and disease processes, anatomy, staging, etc.
And of course, a pathology elective would be a lighter/easier rotation to fill out your 4th year electives. Why not do an elective in something you'll never get the chance to do during residency? You'll get more than enough experience doing procedures, interpreting EKG's, etc., during residency - why blow a 4th year elective on that?
So, I guess if you go into a specialty where you will never send pathology a specimen, never order a blood product, or never have a patient die, then it might not be a good elective for you ;o)