New cleint Item sets

The new client is absolutely great and a upgrade. I appreciate that, but i have a concern about when the replacement is complete. While you replace the old client completely with the new one will the new client already have item sets? Because i don't want to go without item sets for a period of time while you are still adding it which who knows how long that will take. Can they replace the client when the new client has all the features or at least the ones the old client already has? And one more question, When the new client gets the item set editor will our old item sets be transferred to the new one? Because i have made so SOOO many items sets and every one else who uses them has also. Over 100 item sets to the people who own all the champions. And it would be pretty lame if when the new item set tool comes out all of our current item sets will be erased.