The ability to listen to a message while reading other chats and play messages at 1.5 or 2 times the speed will be rolled out in the coming weeks.
The recording of messages is getting better. If you need to have a brief conversation in real life, you don't have to leave large gaps of silence if you pause and resume your recording. You will be able to listen to a message before you send it to make sure you don't accidentally cut off or include something you don't want to.
There is also a slight aesthetic improvement. Instead of using a line to show the progress of your voice message, you will now see the actual message. You don't have to listen to an entire message if you start playing back from where you paused.
The improvements will likely get a lot of use. It's nice to see that the version of the app that lets you listen to messages outside chats is getting some attention.