Vulnerabilities vs Exploits (Score 1)

Perhaps a better statistic to look at if you're interested in which is more secure is the actual number of boxes which were exploited... and I'd guess that last year the windows machines win that category by a landslide.

Of course, it all comes down to the admin in the end, so any talk of which OS is more secure doesn't really mean much. A clueless admin on a very secure OS can still open the gates wide to anyone that tries.