The latest update to the CRAN R archive brings the total number of packages to 9004.

Milestones:

2016-08-22: 9000 packages
2016-02-29: 8000 packages
2015-08-12: 7000 packages
2014-10-29: 6000 packages
2013-11-08: 5000 packages
2012-08-23: 4000 packages
2011-05-12: 3000 packages
2009-10-04: 2000 packages
2007-04-12: 1000 packages
2004-10-01: 500 packages
2003-04-01: 250 packages

There is a listing of data analysis tools for Mac OSX here.