I think it is possible from there to do a function that blurs a texture (returning a new texture that is blurred, the one from the second framebuffer). The only thing is that for now, if the framebuffer is freed, that frees the texture as well. So maybe one function to free the framebuffer but keep the texture would be handy.
Otherwise, to have the information about the vertex coordinate, the way to go with OpenGL 3 would be to use array buffers. I made some classes to use them, even if it is not much official yet.