I'm split on this one. Depending on the case & how the system is implemented, it could be great.
My mother used to work with special needs children of all kinds from deaf or blind to mental handicapped. It could be a great help in those cases. If they get lost in the halls, they could easily be found & helped back to their classes.
Also in worse case senario... say a student is injured & needs medical attention, it makes it easier to direct a medical team to their location & since they're already on a computer pull up records from the nurse office that would show if they had allergies & such.
Having working in the medical field myself, having that info before an ambulance arrives saves time & possibly lives.