Andy Schleck is 26 or 27, has won LBL in 2009 and the Tour in 2010, as was confirmed this week by giving him the yellow jersey officially. He might have earned good money from 2005.
He has reached everything he wanted to reach, and the maximum he can reach, a Giro/Vuelta/Amstel/Worlds/... win wouldn´t change that too much.
Now everything is just for fun for him, as he showed again in this prologue. What did Riis say about Ullrich in April 2006? "Ullrich seems to be unhappy to still be a pro rider", or s.th. like that. It´s the same for Andy now.
He is so gifted by nature, so he doesn´t have to adapt to the cold, the wet, the descents, the attacks, the time trials.
I guess he´ll do a few more years for pleasure and retire then.
Probably he hasn´t improved his time trial a lot in 2012, again... Van den Broeck, for example, has, and so did others, and Andy could have managed that, with Bruyneel and all these guys behind him. Just see how Rasmussen improved his time trial from 2005 to 2007. I guess Andy just didn´t have the motivation, the will to improve this.