Chia-I Wu, the principal developer behind this Intel Gallium3D driver that supports the second and third generations of Intel Core CPU graphics, made the commit this morning to advertise GLSL 1.40 by default over GLSL 1.30 after having support for Uniform Buffer Objects and Texture Buffer Objects.
For those unfamiliar with this Gallium3D driver, read this article with benchmarks cover the work of this LunarG developer. The driver was merged into mainline Mesa this year but isn't exposed by default.
GLSL 1.40 is the version of the GL Shading Language corresponding to the OpenGL 3.1 specification. Meanwhile, the upstream Intel i965 DRI driver has already supported GLSL 1.40 for some time.