2013 is on it's initial months and we already have 5.6 GA and the first release of 5.7, 5.7.1 DMR with lots of exciting new features, future is promising!
A new feature added in replication was the NONBLOCKING option to SHOW SLAVE STATUS command.
In the past if we stop slave during a big transaction, until the transaction was applied we cannot execute SHOW SLAVE STATUS to see the slave progress. The latter operation would block until the former finish, this would disable all external monitoring or third-party applications that need a immediate response from server.
To solve this problem, NONBLOCKING option was added to SHOW SLAVE STATUS, when it is used we can obtain immediate response from server about slave progress. As a tradeoff, the returned info may not be the latest data but it won't block waiting for STOP SLAVE.
This enhancement and many more can be downloaded from MySQL development releases page.