jVSTwRapper v0.8 has been released. This new version features many bug fixes and - most important - full integration into the native plug-in window. There's now no difference between a native and a Java GUI.
Please NOTE that the Constructor of a jvst plugin now has a parameter. Simply pass this parameter to the super class (by calling super(arg)) and you're all set.
Also, the VST Plugins package has been disabled. The latest version of the demo plugins come with the wrapper download itself.