Apparently, and I'm not sure if this is a change and I haven't found any documentation for it anywhere, the "intel" X.Org driver will not permit access to hardware acceleration and the DRI unless the user is a member of the "video" group. That was a good hour of Googling to find.
So, if you use an Intel-based graphics controller such as the Intel 82945G/GZ (or any other 945G chipset controller), make sure to add your primary user to "video" if you want hardware acceleration.
I was wondering why it was using the software renderer; I thought I'd gotten this working last year. Oh, well...working now.