BreezingForms is an enterprise form builder.
MoodThingy is a plugin that any blogger can use to track the emotional feedback of an individual blog post or article.
Jetpack allows you to supercharge your WordPress site with powerful features previously only available to WordPress.com users.
StatComm provides realtime statistics on your blog, collecting information about visitors, spiders, search keywords, feeds, browsers, OS and more.
Theme-Check allows you to run checks on the current theme before uploading to WordPress. This plugin uses the same API and is kept more or less in sync with the WordPress.org uploader tool.