This is a major update. Beyond the fresh coat of paint on the app icon, there are several major improvements. It is available in the Mac App Store.
Some notable ones:
1. Vastly improved group chat (MUC) support. Added bookmarks and auto join.
2. Added jingle VOIP calls support.
3. View what modern XMPP capabilities your server supports
4. Resolved issues with Google authentication
5. Shows offline contacts
6. Many improvements to XMPP carbons and stream resumption