From http://java.sun.com/developer/technicalArticles/J2SE/security/#3:
Note: These two system properties are
ignored when applications run on
operating systems that do not yet
support this feature, for example, MS
Windows.
That document is from 2006, so things could have changed but I've not found a definitive answer.
I would like to know if the latest release of Sun Java 6 for Windows support native GSS today (to get the TGT without tinkering with the registry).
Nope
From http://hg.openjdk.java.net/jdk6/jdk6-gate/jdk/file/78235ae077a1/src/share/classes/sun/security/jgss/GSSManagerImpl.java (47):
47 static {
48 USE_NATIVE =
49 AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
50 public Boolean run() {
51 String osname = System.getProperty("os.name");
52 if (osname.startsWith("SunOS") ||
53 osname.startsWith("Linux")) {
54 return new Boolean(System.getProperty
55 (USE_NATIVE_PROP));
56 }
57 return Boolean.FALSE;
58 }
59 });
60