Get it at the homepage
Read the baseline whatsnew right here
SDL-wise we've got additional fixes for the upcoming switch to compiling as C++, general SDL layer cleanups, improved -verbose output to help diagnose errors, and improved SDL 1.3 SVN support from couriersud. And Skito contributed a fix to controller button enumeration.
Smoke tested on Fedora 12 (x64) and Mac OS X 10.6.2 (Intel with the latest Xcode updates applied)
Win64 and (Intel) Mac 64-bit support will become official in u1. Stay tuned.