Amongst the key features are automatic update checks once per day or week, Growl notifications, powerful configuration possibilities and an extensive documentation built right into the widget (but you can also read the documentation in your browser).
Press Shift+H at any time to bring up the help, more...
- Fixes a crash on Snow Leopard.
- Fixes a potential hang when checking MacUpdate.com.
- Mentions that Spotlight must be enabled when no apps/widgets are found.