In Ogre 1.6.0 RC1, SceneNode::getWorldPosition() and SceneNode::getWorldOrientation() was removed. A topic of the forum reports that some developers who changed their engine to 1.6.0 get errors at compiling.
Changelog explained those two methods were removed from Renderable interface. At the same time, those methos were removed from SceneNode class. The engine gets full transform matrices from Renderable interface, so it doesn't need getWorldMatrix() and getWorldOrientation(). We may use _getDeriveedPosition() and _getDerivedOrientation() instead of the removed methods.
getWorldPosition() and getWorldOrientation() were pure alias methods. Therefore, you may add those alias methos to OgreSceneNode.h of 1.6.0. Even if you do this little hack to a header file of the prebuild SDK, you don't need to re-build the engine.