Seam 2.0 works with Netbeans 6.0 M10 and the Netbeans Seam plugin. I've spent some time preparing an application based upon some of the examples given in the Seam 2.0 documentation.
I've managed to deploy and successfully run an application on JBoss 4.2.0 using Netbeans 6.0 M10 and the seam plugin. I only used the plug-in to generate the initial application. I did not use any of the other plug-in automation.