Thanks for the feedback! Just to be clear, keeping GL2 support wouldn't just be for supporting ancient hardware, but also for supporting more modern implementations that just lack specific features that prevent it from claiming full GL3 support.
That said, however, I've decided to go ahead anyway and limit support to OpenGL 3. Partly because noone has really spoken up in support of OpenGL 2 support, but also because there are a few features in OpenGL 3 that would be really nice to have for future improvements (most importantly array textures, FP textures and vertex texture fetch).