I have updated the OpenGL Hardware Matrix for OpenGL 3 hardware to include Sandy Bridge GPUs. Unfortunately, Intel has gave up on improving the OpenGL support of Sandy Bridge GPUs on Windows despite still shipping processors using this architecture.
Worse, Intel OpenGL implementation for Sandy Bridge only supports OpenGL 3.1 and a major part of OpenGL 3.2 and OpenGL 3.3 extensions but ARB_geometry_shader4 (3.2), ARB_texture_multisample (3.2), ARB_blend_func_extended and ARB_texture_swizzle. Interestingly, Sandy Bridge supports a single OpenGL 4.0 extension that is ARB_texture_query_lod. Not even ARB_debug_output or ARB_ES2_compatibility.
The status of Sandy Bridge on Windows might be leading OpenGL programmers to quite some headaches when shipping a product that needs to run on a large and broad install base. It's annoying already, picture that in 3 or 5 years.