Here are the most visible changes (from the user and dapp developer perspectives):
- The L1 security fee is lower. Bedrock will use a much more efficient compression algorithm, and avoid calling a CTC chain contract.
- Blocks are produced every two seconds, regardless of the number of transactions. Some blocks will be empty, others filled to the block gas limit.
- OP Mainnet uses the same EIP 1559 mechanism as L1 Ethereum (for the L2 execution fee).
- Rather than accepting or rejecting transactions immediately, the sequencer will store them in a private mempool, and use priority fees to order them.
- Deposits (transactions from L1 Ethereum to OP Mainnet) will be processed by verifiers even when the sequencer is down, so the sequencer will be unable to delay transactions submitted on L1.
Note that this was not a regenesis. The transaction history since November 11th, 2021, will stay available.
For more detailed information, see our developer docs.