I believe that is about it! At this point you should have a fully functioning OpenGL system for running and developing OpenGL apps.
You can try building the demos in /usr/src/Mesa-4.0.1/{demos,xdemos} by using the Makefile.X11 as Makefile and running "make targets" or "make teapot" etc. They should build and link with the hardware accelerated libGL and run very fast! Qt has a OpenGL example in $QTDIR/examples/gear, that you should be able to run as simply as "make;./gear".
Just about any standard GL/GLX/GLU/glut app should run fine, such as WolfGL, GLQuake, glqwcl.glx (GLQuakeWorld), quake2, and of course ... quake3!!!
HAVE FUN!