Courtney Goeltzenleuchter of LunarG has sent out a set of seven patches for providing GL_ARB_texture_view support while seperately there is KDE's Fredrik Höglund that's still tackling GL_ARB_vertex_attrib_binding.
ARB_texture_view is written against the OpenGL 4.2 Core profile and required for the OpenGL 4.3 specification. The extension allows a texture's data store to be viewed in multiple ways. This work for ARB_texture_view by Courtney at LunarG is spread over seven patches but only just lays the Mesa core groundwork and doesn't provide the support to any of the hardware drivers. Those new patches can be found on the Mesa list.
ARB_vertex_attrib_binding is also written against the GL 4.2 Core specification, required for GL 4.3, and allows for applications/games to change the mapping between vertex attributes and vertex bindings. This extension makes it more efficient to update vertex buffer bindings for interleaved vertex formats. Implementing the vertex attribute binding support in Mesa is spread over 11 patches and currently up to its second revision. Those current patches can be found on the mailing list as well. The GL_ARB_vertex_attrib_binding support is provided to all Mesa drivers.