I have updated my cycling data page with 2011 Giro info and other things.
The 2011 Giro was advertised as the hardest one in recent memory. But, the data doesn't suggest that it was particularly hard, with one exception. The lantern rouge time is higher than any other Giro going back to at least 2001, but just barely. On the other hand, the percentage of riders finishing is actually on the high side, and it was the fastest Giro I have data for.