JohnRoy - 2:02 am on Aug 24, 2011 (gmt 0)
I would call it change in algorithm. For many this is a routine, you're lucky you were #1 for years.
What do you call it when you are about -10 for your main keyword? In our case we went from #1 for years to about #14 and stayed there for the last several months.
No. Your site does not appear to be penalized.
Would a reinclusion request have potential for benefit?