What changed for L2s after Fusaka?

TLDR

Ethereums Fusaka upgrade changed L2s by introducing PeerDAS and a staged increase in blob capacity, enabling higher throughput and lower data?posting costs for rollups per the Ethereum announcement.

1. PeerDAS lets nodes sample blobs, raising L2 data throughput and lowering DA overhead per the Tokenpost report.
2. Blob counts rise via BPO forks (Dec 9 and Jan 7), expanding L2 posting room and stabilizing fees per the Ethereum post.
3. Foundations for based rollups could shift L2 MEV and sequencing closer to ETH validators per the Nansen analysis.

Deep Dive

1. PeerDAS and Capacity

PeerDAS (EIP?7594) means validators no longer download full L2 blobs; they sample small parts to verify availability, cutting bandwidth and easing node requirements. That allows more blobs per block, boosting rollup throughput and reducing L2 data?publication overhead. The upgrade was confirmed with synchronized execution and consensus changes and went live smoothly at scale per the Tokenpost report.

• The official plan increases blob capacity in controlled steps via Blob Parameter Only forks, raising the target from 6 toward 10 on 9 Dec and 14 on 7 Jan, with max bounds of 15 and 21, respectively per the Ethereum post.
• OP Stack teams highlight that this path gives chains more blob room and lower fees while keeping decentralization intact per the Optimism thread.

2. Fees and Blob Economics

Fusaka introduces blob base?fee tuning (EIP?7918) to stabilize costs as capacity rises, aiming to avoid extreme swings, while staged capacity boosts broaden posting room per the Ethereum post above. Early commentary emphasizes lower average L2 costs as PeerDAS scales blob space and reduces DA overhead per the Binance Square summary.

• Some observers noted near?term blob?fee volatility after activation, with expectations that capacity steps (BPO1/BPO2) should ease pressure as the system stabilizes per the Ethereum post above.
• The Defiants coverage frames this as the first stage in L2 data scaling, with increases slowly and methodically to preserve safety per the Defiant article.

3. Sequencing and Value Capture

Analysis suggests Fusaka lays groundwork for based rollups, where ETH validators could sequence L2 transactions, aligning incentives and potentially directing more economic activity (MEV, preconfirmations) to the base layer per the Nansen analysis.

• If L2s adopt validator?based sequencing, ETH fee burn and staker rewards could rise with higher blob demand; the model is optional and depends on L2 choices per the Nansen analysis above.
• Fusaka also adds secp256r1 precompile and deterministic proposer lookahead, improving wallet UX and enabling near?millisecond preconfirmations that L2 stacks can leverage per the Ethereum post.

Conclusion

Fusaka primarily changed L2s by making blob data handling far more efficient and expanding capacity, which should lower data?posting costs and increase throughput as staged BPO forks come online. If L2s embrace validator?aligned sequencing, more activity could accrue to ETH, but that shift is discretionary and will unfold over time.