Just to be clear . . . "French vineyards probably have, but I am willing to be corrected, the widest variety of grapes of any country in the world." (from Norris) is incorrect.
Italy has the widest variety of grapes. As of December 2005, there are over 340 varietals with some sort of classified significance. Including non-native grape varieties, it is estimated that there are between 2000-3000 varietals in Italy alone. In the last decade or so, France and Italy have been trading back and forth the honors of top producer, with France just edging out Italy in 2005.
In case you are interested: http://winesoc.eusa.ed.ac.uk/
dan polito
cleveland, OH