http://javatoolbox.com is a new directory of the existing development tools, libraries and plugins for Java/J2EE. It lists freeware, open source, as well as commercial products, all organized in multiple categories.
There is still a lot of tools to add to the site, but it should grow quickly. RSS feeds and newsletters are available to let you know about updates. Currently JavaToolbox references more than 270 tools in 42 categories.