Putin is too young to feel like retiring. From an interview with Medvedev:
On whether Putin should assume a role that has been described as "national leader":
"It is difficult for me to comment on a decision of President Putin; he makes them himself. He's the president. As for his plans for the future, he has not revealed them. He has said, I think, with a certain level of clarity, with a sufficient level of clarity, that he would not like to remove himself from future political activities. And under certain conditions, in particular the victory of United Russia in the elections and the formation of competent Parliament, he could become one of the most active participants in political life and might become the prime minister. Although this could only occur under the conditions that he discussed, and of course depends on his willingness to continue.
"I will consider as a lawyer the legitimacy of some kind of special role as leader. Our Constitution does not contain anything about a special role. We have a president, a very strong figure. He is the head of state, the guarantor of the Constitution. He formally has no relation to the legislative branch, though he participates in its creation. We have a strong government under the leadership of a prime minister. We have a Parliament, we have a justice system, and not a separate position of leader or anything else.
"I believe, however, that everything that is now being said on this issue is also an element of political competition. It is completely normal. Everyone knows that President Putin has done a lot, and has worked for the development of the state. And the desire of political forces sympathetic to President Putin for him to remain a key political figure in the future is understandable. That's why discussions about creating a special position for him have arisen. Understand that there are laws, not just God-given laws or laws that govern the political sphere, but also those that govern the legal sphere. While these laws remain unchanged, the system that currently exists will remain in force. This problem must eventually be solved within the framework of existing laws.
"If the acting president, Vladimir Vladimirovich, hopes to continue his work, then it will be in a position that is outlined by the Constitution."
http://www.iht.com/articles/2007/12/11/europe/11interview.php