Blender 2.60 is being worked on
According to minutes from the last meeting of Blender developers work on 2.60 has started, with some exciting new fetaures already making their way main SVN branch.
The new version, currently planned for October, is going to feature the "Pepper" branch that contains the following Google Summer of Code 2011 projects: animation system polish, 3D audio, motion capture tools, BGE animation improvements and COLLADA improvements.
Edit: As of August 30 afternoon, the Pepper branch is already in trunk. Give it a jolly good test, folks!
VSE Proxy branch has already been merged, and vgroup modifier is currently under review, with Ocean Sim already submitted for 2.60, but lacking a dedicated reviewer. New patches for 2.60 will be accepted till end of this week.
It's still not clear if GSoC project that brings back localization of Blender's user interface willl be ready for 2.60. Even if it will, translators are going to have a hard time: some of translations (like the Russian one) haven't been touched for 5 to 8 years, and the changes between 2.4x and 2.5x are rather dramatic.