I wrote about this a bit in the episode discussion thread for the finale, but I think this first season did enough to justify itself, even if it didn't do much more than that. I thought the story was interesting enough that I am intending on starting the manga (which is really what they want). The first season really felt like it was just scratching the surface of a much larger world/story.
One thing I do hope is that the show did well enough that they decide to invest more into the production side of things. The animation was never great (either the action or the ecchi). If they really want this to make waves, it could do with investing into better animation on one side of the show or the other.