I read where there is a controversy surrounding the time change, competition will go from 12 minutes down to 10 minutes. Joey Chestnut ate 66(new record) last year and that was a 12 minute competition. Under seems like a good bet to me if you can afford the juice.
prices @ 5dimes:
Nathan's winner eats over 68½ hot dogs +300
Nathan's winner eats under 68½ hot dogs -420

prices @ 5dimes:
Nathan's winner eats over 68½ hot dogs +300
Nathan's winner eats under 68½ hot dogs -420