The guy has stated that his wish is to play for Real Madrid. But it is not the right time to do so.
1. He can't get the consistency that is seen in Man Utd. Wesley Sneijder said before that he will try to outdo him at everything if he happens to move to the club. Learn the lesson from David Beckham. He achieved great success at Man Utd. When he moved to Madrid, he won nothing, sometimes at bench and only won one league title.
2. Madrid has a chairman that doesn't really understand football totally like the Glazers / or Martin Edwards. Ramon Calderon made some fatal mistakes in the past, including throwing coaches like Fabio Capello, Vincente Del Bosque and Guus Hiddink despite leading to club to silverware like league titles and Champions League.
3. They still do not learn the lesson from the Perez mess. Fiorentino Perez spent a lot of money to build Galaticos but they get nothing...no silverware but stardom.
4. Ronaldo still has more medals to be added. Coming in December, he will get his chance to win an Intercontinental Cup medal / World Club Championship (so to speak) and he has the chance to win more.
5. 42 Goals and the chance to become European / World Footballer of the Year...very good! He'll be needed badly for the next campaign to hold off challengers like Chelsea, Liverpool and Arsenal.
6. He has signed a deal until 2012 since 2007. He should commit himself until 2010 and then move. Doing so is violating your promise to the club. By the time 2010, the contract protection period is over and he is welcome to talk to other club without asking permission.