Can I use NetBeans to build my Java EE 5 application?

The short answer is Yes.
NetBeans has supported developing Java EE 5 modules and applications for two releases:
There is info on using NetBeans 6.0 for developing Web components and other Java EE 5 artifacts. There is also information about [using NetBeans
5.5 to create web and Java EE 5 artifacts|http://www.netbeans.org/kb/55/web-javaee-index.html].