Use PHILO_MIDDLEWARE in place of signals.
We currently provide a view_about_to_render signal, which is good. It lets developers take action when the page renders, such as inserting arbitrary values into the extra_context of the view. However, things like form handling are impossible, because a) one cannot guarantee that receivers will be processed in any particular order, and b) one cannot replace the returned response with e.g. an HttpResponseRedirect without overriding the view's actually_render_to_response method; this is extremely hackish.
I think it would be useful to use a middleware-like arrangement instead of signals.