One again good news for Mac lovers 
(i am one of em)
So lets see what’s new
- Performance and memory bug fixes (over three dozen).
- Clearer messaging when receiving anonymous messages from your Pingbox.
- A new message style called ‘Kobi lite’ . To try it out, go to Preferences > Messaging, then change the Conversation style.
- If you want to cancel automatic sign-in when you launch Yahoo! Messenger for Mac, hold down the shift key.
- When you report an IM as spam, it also adds the sender to your ignore list .
If you want to participate don’t hesitate to send your feedback