Smarter code completion
Better Navigation and Inspection
More than just code completion
Ruby/JRuby/Ruby on Rails Support
Advanced Ruby Editing
Ruby on Rails Support
Easier Installation and Upgrading
Unified installation experience
Swing GUI Development
Swing Database Applications
Swing Application Framework (JSR 296) support
Profiler integrated into NetBeans IDE.
Compare Memory Snapshots
Dynamic Attach on JDK 1.6.
Web and Java EE
Built-in visual design for web applications.
Visual page flow editing.
Enhanced web services support.
Support for Ajax-enabled JavaServer Faces components.
Easy migration from Java Studio Creator
Enhanced CSS editing.
New Integrated UI for CLDC/MIDP and CDC development.
New game builder.
New Visual Mobile Designer.
New custom components.
New components for Flow Control.
Generated code is now easier to modify.
Re-written JSR-172 stub compiler.
Improved project configuration management.
Artifacts for service composition and assembly.
Graphical WSDL editor.
XSLT editor to edit transformations
Tooling support for binding components.
Java EE Web Service project support
Template based code generation now available and customizable.
Enhanced code generation feature.
Improved collections management.
Alignment Tools now available.
New Window Layout.
Save As action now on diagram node
For more details read nenbeans documentation