C.G.
I think you should read his cues as to when he is ready to cut down to just one nap or change his nap schedule. Getting enough sleep in critical to his development, and just because he hit that 1 year mark, doesn't mean he needs less sleep--unless he is showing it.
I would keep him on his consistent nap schedule until you see signs from him--like not being tired at his usual nap time, unwilling to fall asleep. Then you may be able to gradually cut back on one of his naps--like taking two naps some days if he needs both, and only one on other days if he's not as tired.
I used to work in a one-year-old classroom and there were several children who still needed two naps well into that year.