The official download page for Blender 2.43 is still pointing to the old 2.42 demo files. Here are the latest 2.43 demo files:
Game Demos Physics 2.43:
http://download.blender.org/demo/test/physics-2.43-physics-testfiles-5.zip
Game Demos Graphics 2.43:
http://download.blender.org/demo/test/graphics-demos-2.43-preview1.zip
Also there is the physics contest, with Playstation 3 prize. Registration information is now available here:
http://www.continuousphysics.com/Bullet/phpBB2/viewtopic.php?t=752
Enjoy!
Erwin