RIM appears to have released v 1.0.0 (Build 75) of the Blackberry Desktop for Mac.
Before downloading I suggest you read this article at the San Francisco Chronicle.
For more detail on RIM’s new BlackBerry software for Mac, including differences between the Mac and PC version, read “Four Things You Didn’t Know About BlackBerry Desktop Software for Mac“.
Grab your copy of BlackBerry Desktop Software for Mac v 1.0.0 here or here before RIM locates it and starts removing it from the web.