Ongoing Onchain Proposals 
1. [CONSTITUTIONAL] AIP: ArbOS Version 40 Callisto (Voting ends May 29)
This AIP proposes to upgrade Arbitrum One and Arbitrum Nova to ArbOS 40 “Callisto.”
Callisto adds support for relevant Ethereum Execution Layer (EL) changes from Ethereum’s recent Pectra network upgrade and includes a minor fix related to Arbitrum Stylus.
Among the EL changes introduced are a way for Externally Owned Accounts (EOAs) to execute smart contract code directly from their own addresses (via EIP-7702) and new precompiles to efficiently perform operations over the BLS12-381 elliptic curve, including BLS signature verification (via EIP-2537).
Ongoing Temperature Checks 
1. [Constitutional] AIP: Constitutional Quorum Threshold Reduction (Voting ends May 29)
This AIP proposes to reduce the constitutional quorum threshold from 5% to 4.5% of votable $ARB supply.
This is to ensure that well-supported proposals can successfully conclude by aligning quorum requirements with current levels of voter participation, reducing the risk of legitimate initiatives failing due to quorum thresholds not being met.
This proposed 0.5% reduction would be a short-term adjustment that enables critical governance to move forward while longer-term reforms are considered and developed.
Other Reminders 
1. March 2025 Security Council Elections - Complete
The Security Council Election process for the March 2025 cohort is finally complete, as election results have taken effect across relevant chains.
Please welcome the newly elected members: fred, bartek.eth, Michael Lewellen, yoav.eth, Certora, and OpenZeppelin.