Right, I should have said that when I was talking about the ``WCS`` class, it doesn't have to be FITS WCS only. In my mind, ``astropy.wcs`` was intended to contain any WCS system in the long term, so that's why I see WCSAxes living there. However, if you still think it would be better to have it elsewhere, we could have an Astropy sub-package dedicated to plotting, e.g. ``astropy.plotting`` or ``astropy.graphics`` where other Astronomy-specific visualizations could live? I don't think this is an important point for now though, as I think we'll start implementing it as an affiliated package anyway until it's ready for inclusion, at which point we can decide where it should live (and by then, maybe we'll have made a decision concerning the generalized WCS).