Well, well, well...it seems they're listening.
"Astana was initially thinking about taking Nibali to win the Giro, but the plan may be changing. The Kazakh team may have him skip the race all together for
a chance at winning the Tour."
"He left the Tour with the knowledge that he can play for any stage race [win] in the future without fearing his rivals,” long-time trainer, Paolo Slongo told VeloNews. He won’t start the next year saying, 'I hope to be up with the favorites'. No.
He will start as a favorite."
http://velonews.competitor.com/2012/10/news/vincenzo-nibali-deciding-between-giro-and-tour_240549
One thing seems for sure, he won't do both, Giro and Tour.