As of 2014, around 250 legally dead people in the United States were in cryonic preservation. At least 1,500 people around the world have active plans to join them in cryopreservation in an attempt to thwart (or at least delay) permanent death by freezing (or more technically 'vitrifying') their corpses after their legal death. Many of these 'cryopatients' have had their whole bodies preserved; others have opted to have only a cheaper neuropreservation. You can probably guess what that means. For more information on the current state of the art in cryonics, you can visit Alcor's website, which is one of the most prominent organisations in the field.
This question asks: will any 'patients' who have been in cryonic preservation for at least one full year before 2050 be successfully revived before 1 January 2050?
For the purposes of this question, a revived patient must be determined by at least three recognized medical experts (M.D. or PhD in Biology, Neuroscience or equivalent level of education), each of whom is independent of the cryonics organisation responsible for the patient, to be conscious, alert and responsive to questions for at least 24 hours at some point within a year and a day after midnight on the date that the attempt to revive them is made.