Why is OpenGL 2.0 needed for XBMC?
OpenGL 2.0 is not really the current minimum requirement to run XBMC for Linux, as in reality XBMC will today run with only OpenGL 1.3 + GLSL support (everything else has fall-backs to be runned in software on the CPU, slower than GPU hardware though), however to be sure to stay future-proof Team-XBMC have decided that the OpenGL 2.0 is the recommended minimum requirement.