Patch in place features were integrated into 6u10 b07. L10n of the feature should follow in later builds of 6u10, possibly b10.
For information of patch in place, refer to
http://j2se.sfbay.sun.com/web/bin/view/Deployment/PatchInPlace
section 2 in
http://web-east.east/www/tests/getjava/wat/