Lee Sin is a very versatile champion, but despite his versatility, it is rare to see him in the support role.
There are many reasons that make Lee Sin a great addition to the team, he is very much a utility player as far as I am concerned, he has a lot of damage, and natural defense to keep him safe. Sightstone is a valuable buy on Lee Sin, because it essentially gives him a flash every 9 seconds when combined with safeguard. His Tempest/Cripple is very effective vs attack speed dependent enemies, and the movement slowing effect gives the enemy a shorter chance to escape without blowing their summoners.
Dragons rage is a great tool for both peeling, and making picks on the enemy. A well known Lee Sin combo, often referred to as the 'Insec' maneuver consists of the player engaging on the enemy with sonic wave/resonating strike, following up with a ward/safeguard combo, or flash behind the enemy. And kicking the enemy into your team, leaving them in a difficult situation, which likely results in them losing their life.