Both the Lineage 2 forum and the official website has announced that the Gracia Epilogue is due to be launched on the Lineage II public test server on Oct. 29 and all players are encouraged to try Gracia Epilogue out.
"Gracia Epilogue^TM will be arriving on the Official Lineage II Public Test Server on Thursday, October 29th, 2009. New quests, hunting grounds, improved vitality and more await you in this final installment of Gracia. Check out the Gracia Epilogue Preview Site for a sneak peak of what is in store for this update."
In addition, players will have to download the official Lineage II Public Test Server client first, which is claimed to be available soon. As for the patch notes, it still says coming soon.