A few release notes for the PC versions:
The Linux binaries were built with GCC 4.3 (stock Fedora 9) this time. AFAIK any GCC 4.x-based distro should be compatible, but let me know if you have shared library issues and I can rebuild with compat-gcc like the previous versions.
Both the Linux and Windows versions now add an icon to your system tray which you can right-click to get a popup menu and control things. This is arguably most useful on Linux with multiple desktops, but if you want to load up a playlist and hide AO on Windows it's handy there too.
Like the recent betas, the Windows versions are built with Visual Studio 2005 SP1. If you get a configuration or missing DLL error, you need to run Microsoft's installer for the updated MFC libraries: 32-bit