Really good documentation to Blender / Python programmers.

http://www.blender.org/documentation/244PythonDoc/index.html 

More information here:

http://www.blender.org/development/release-logs/blender-245/ 

Source: www.blender.org

"More bugfixes are going to make it in 2.45... so here's another candidate for testing.

Blender 2.45 is going to be a bugfix release, to stabilize the 2.4x series.
No new feature have been added, but serious effort has been put in tracking bugs and fixing them. Some performance issues have also been addressed.

Here you can get the 2.45 release candidate #2:"

download.blender.org/release/Blender2.45rc/