update VERSION in several places (/VERSION file, /CMakeLists.txt, /configure.ac, /src/LinearMath/btScalar.h, /src/LinearMath/btSerializer.h around line 441)
re-generate serialization structures, if they changed (/src/LinearMath/btSerializer.cpp using makesdna)
update ChangeLog with larger/important changes
regenerate MSVC project files using build/vs_all.bat
create a Subversion tag revision in bullet.googlecode.com/svn/tags/bullet-<VERSION>