Note: This entry has been posted on 1. April 2008 and nothing of that below is true :-)
You probably already know a lot of changes are planed for the NetBeans 7.0 release.
One of the bigger changes is tighter integration to the Windows Presentation Foundation for the SWT/JFace rewrite of NetBeans 7.0 similar tho the Eclipse roadmap. The minimum system requirement will rise to windows vista ultimate with a DirectX 10 capable graphics card and a USB stick plugged into your system (swap file for java quickstarter) to render NetBeans 7 in full HD. The primary reason for that was the out of the box Java 6 incompatibility to apple systems (who knows maybe it is compatible with MacOS X but no one will tell you because if he tried installing SE 6 on macs he/she also signed an NDA...) and the issue that many architects simple do not understand the internals of linux distributions (e.g Ubuntu) to install NetBeans.
On older cards or other operating systems JEdit will be started in compatibility mode (motif look&feel and full shell support).
The reason for that are the new consumer guidelines and download size limitations of the java 6 Update 10 release. (there is a because of backwards compatibility problems [to build 11] not fixable ArrayIndexOutOfBounds bug in the pack200 implementation - primary reason why the swing renderer does not fit into the NB 7 distribution anymore if started with Java 6 update 10).
This brings several advantages. E.g instead of playing Jake in the browser (update 10 required) NetBeans 7.0 will be capable to render Halo 3 in the editor pane (with full profiler integration and 16x FSAA text overlay). Regular patches will be available via update center.
Additionally to that better joystick support is planed. This should improve the navigation through larger projects and replace the "go to declaration" action. You may also activate the force feedback option in the new "user experience" tab in the options dialog to detect the files which causes unit tests to fail. (Note: not available in JEdit compatibility mode but there will be a blinking icon instead)
The higher costs to develop NetBeans 7.0 make a complete free distribution not feasible but it will be still free for opensource developers (but not without limitations e.g UML diagrams will be limited to only two kind of widgets "hack" and "ship" while maintaining 100% SSP compatibility).