Using the projects build obtained from the page:

http://www.netbeans.org/download/prj40_prototype/night/buil
d200211201600/index.html

Performing the following steps: 

1:  Create a new java package under src
2:  Create a new Java file within the package.

The templates do not appear to be fixed up with the proper 
names. I tried a new Main and a new Class and both were 
left uncompilable.

I named the new "Class" file "xab", here is the result.

/*
 * xab.java
 *
 * Created on November 20, 2002, 2:35 PM
 */

package Templates.Classes;

/**
 *
 * @author  ottati
 */
public class Class {
    
    /** Creates a new instance of xab */
    public Class() {
    }
    
}

I named the new main class "HelloWorld" here is the result.

/*
 * HelloWorld.java
 *
 * Created on November 20, 2002, 2:27 PM
 */

package Templates.Classes;

/**
 *
 * @author  ottati
 */
public class Main {
    
    /** Creates a new instance of HelloWorld */
    public Main() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
    }
    
}