I am working on a project which has many jar dependencies. To make things easy they are located in a single 'lib' folder. I point netbeans to use the folder however it the classes are not resolved. Howeverwhen I add the jars directly then everything is resolved as expected. Java 1.6 allows the use of a wildcard to include all jars in a classpath so it seems it would be possible to include a file of jars and have them all included in the project classpath.
Currently the JARs must all be added, since adding a folder to CP means it contains unpacked classes. Note that you can multiselect JARs in the file chooser. No support planned for adding a wildcard since this is tricky to support in the Ant script.