Zcash developer Sean Bow reported significant progress in preparing the Ironwood upgrade. All consensus changes have been implemented and are undergoing audit; the specifications have been published. The testnet activation is scheduled for tomorrow, and mainnet launch is expected around July 21.
The only caveat: some wallets may not have enough time to prepare for the upgrade; however, the team believes this is not a sufficient reason to postpone the activation.
The upgrade is particularly important in light of the recent vulnerability incident in the shielded pool—Ironwood should address concerns about the integrity of the ZEC offering.