Mentioned in the 2.64 BGE log is a "Character" physics type. You can try this out now. I did it on my
MacBook but hopefully it will work for Windows and Linux. Go to: http://builder.blender.org/download/ and get the latest Blender Build.
At http://projects.blender.org/tracker/?func=detail&atid=127&aid=28476&group_id=9 click on
Attachments and download character_demo_new.blend.
Use the latest Blender build to open character_demo_new.blend
Move the cube via the x and z keys.
Thanks to Denis Washington for doing this.