The Mayfair site does say "Out of print" for 3rd edition, and "PreOrder" for fourth (just ran and checked)...
We are pushing to get copies of the new edition at Gen Con; it'll be a near thing, but our fingers are crossed. It should be through distribution a couple-few weeks after that, so September should be a safe call, and early if we're lucky.
I preorded the game too. Thanks for update. Any news on Clash of Wills:Shiloh? I preordered through Mayfair site and there was an 8-23 streer date. Will that happen?