Two years ago when floating-point support for Mesa came about and was merged in April of 2011. "Pushed to Mesa master over the night was Marek Olšák's patches for float textures in supporting the ARB_texture_float extension and render-buffers, which is part of the OpenGL 3.0 specification. Marek's work is fully supported in the ATI R300 Gallium3D driver while other drivers can now easily hook into this newly-added support that up until now was living in a branched version of Mesa."
The floating-point feature though for the hardware drivers was not enabled by default but rather concealed behind a --enable-texture-float build-time switch. Due to the legal worries, they punted the problem off to distributions and their packagers or end-users building from source to decide whether to enable this support.
Evidently, Intel is now comfortable with the legal situation concerning OpenGL floating-point textures at least when running on their hardware, so their open-source driver is now always enabling it. Per this commit today, we now have "i965: Enable floating-point textures always." Whenever Mesa 9.1+ is now built, floating-point textures will be present for the Intel DRI driver.
With this change, OpenGL 3.0 (or OpenGL 3.1 for the core context) is also now always exposed as without the floating-point support, the Intel driver has been limited to exposing OpenGL 2.1 compliance.