Most Mac OS X inspired Wordpress themes I’ve seen are mostly mashups of graphics from Mac OS X or its applications. Instead of duplicating OS X, Robert Hodgen has created a great theme providing the OS X atmosphere. Highlights under links, a glossy look and many more tiny details make Blue X a great theme.
The author has provided a comprehensive list of features and screenshots on the theme which is compatible on most browsers. Blue X is a free wordpress theme and it works perfectly on the latest version of Wordpress(compatible Wordpress 2.6).
Also, make sure to check out, Retro Glass which is an OS X inspired Wordpress theme by the same author.
