EDIT: This question has been resolved. You can upgrade and keep your heros and items.
Also when you get the upgrade, make a new hero and put the stuff in the share stash then delete the hero if you want. It will work on all of your old heros. Also also you can still buy this edition for a good enough price. Also also also, in order to give your SE to a friend calling or sending blizzard a ticket is the way to go. I recommend calling because they service, at least mine, was great. Finally you can no longer do that 4 month WOW thing.