He's a very talented player no doubt, but his lack of development is disturbing- he is exactly the same player now in his 3rd year that he was as a 19 year old rookie. He is still young so he certainly still has the potential to get better, but its not a good sign.
In a lot of ways he reminds me of Ricky Rubio (though obviously their games are completely different). Both guys came into the league showing such a high skill level (Kyrie's shooting, Rubio's passing and defense) that people got carried away thinking how good they were gonna be 5 years down the road.
But potential is far from a guarantee, and the NBA is filled with talented guys who seemed to have so much potential at one point. Sometimes its a mental thing, sometimes its just playing for a bad organization.