Google patches V1 contain interesting patch to mirror binary log on slave. Although Google is preparing GlobalTransactionId patch, which going to be replacement for MirroredBinlogs, we still think mirroring binary logs is very useful for:

Backup of binary logs in real time

High availability, to switch master load to slave with mirrored binary logs

By request of our friends EngineYard we extracted this patch from Google’s patchset and going to include in our next releases. Actually our patch contains features for both MirroredBinlogs and FastMasterPromotion patches, as second provides feature to make slave as master in case of main master failure.

At this moment you can download patch by itself there

https://www.percona.com/mysql/5.0.67-b6/patches/mirror_binlog.patch

with docs on our wiki

Also the patch will be included in OurDelta binaries beside our releases for CentOS / RedHat platform, so you can download and test this feature for your OS.