You'll need the latest Netbeans 6.1 beta daily build to get it up and running.
Then download the daily JavaFX plugin archive (ZIP or TGZ) from their Hudson build server.
- Install Netbeans as usual.
- Modify the Netbeans config file under [netbeans-install-dir]/etc/netbeans.conf and include the -J-da option inside the quotes for parameter: netbeans_default_options If you don't the JavaFX compiler won't work because of a bug
- Unpack the JavaFX plugin archive
- Start Netbeans, go to Tools > Plugins > Download
- Click add plugins...
- Select the .NBM files you unpacked from the plugin archive
- In Netbeans go to Tools > Libraries
- Select JavaFXUserLib
- Modify the provided javafxc.jar, javafxrt.jar and Scenario.jar with the ones you prefer