I've counted 14 realistic chances and some of them already rode the Giro. Obviously there can be others who can pop out of the pack. But I did write some people off.
I would say right no you can't count out them: Contador, Andy, Evans, Menchov, Wiggins, Lance, Kreuziger, Basso, Gesink, Lance, Van den Broeck, Luis-Leon Sanchez, Rogers, Samuel Sanchez, Sastre, J. Rodriguez, Brajkovic, Klöden, Leipheimer, Tony Martin, Fuglsang...
Couple of those are long shots but that's a long list.