Looking for your multi- or mega-region? As of 9th December these will be automatically replaced by VarRegions to improve compatibility with core OpenSim. This may affect OARs, terrain textures and landmarks. Otherwise it should be business as usual. See the Kitely blog for details. The update also fixed issues with searching for certain types of world name, speeded up loading of objects into the Contents tab when editing and added a large number of fonts to the OSSL-based drawing capability (OSSL extends SL scripting to allow scripts to draw and write on prims).
VarRegions (Blog): http://bit.ly/1XYM5pd Fonts (Forum): http://bit.ly/1Y1QAza