3. Dr. Boyce
A sly one that many surely missed, when Kirk wakes up in hospital in San Francisco, the doctor's name on his bed's monitor is Dr. Boyce, the same name of the Chief Medical Officer who appeared to counsel Pike in the Star Trek pilot episode, "The Cage". Though this one is pretty surreptitious and doesn't go the full hog of having us meet the character - who was famously acerbic and carried a Martini kit with him - it's still a nice nod that hardcores will no doubt feel proud for catching.