I don't know about the Intel hardware specifically, but OS X 10.7 supports OpenGL 3.2, and the checks Michael performed are incorrect for testing the supported version of OpenGL. The glxinfo command will "lie" to you, because Apple did the awesome and made the OGL 3.x implementation Core Profile only. The glxinfo command is showing you the compatibili ty profile, which is limited to 2.1. Unfortunately, I don't know of any command line tools to print out Core Profile information (there's no glxinfo3 or anything like that), which was something lame that Apple overlooked.
If you get the OpenGL Extensions Viewer 4.0 (free in the App Store), it can show you both the Compatibility Profile and Core Profile information. Note that it defaults to the Compatibility, so when you first run it the version is shows is 2.1. In the middle drop-down on the main window of the Extensions Viewer, select the Core option. Then it'll show you 3.2, at least on the $799 Mac Mini (with the AMD GPU).