On 6th of March, Simon Riggs committed patch: Efficient transaction-controlled synchronous replication. If a standby is broadcasting reply messages and we have named one or more standbys in synchronous_standby_names then allow users who set synchronous_replication to wait for commit, which then provides strict data integrity ...

On 7th of January (I know, it was quite some time ago, I apologize for delay) Itagaki Takahiro committed patch: New system view pg_stat_replication displays activity of wal sender processes.   Itagaki Takahiro and Simon Riggs.