I thought at first that he had been knocked down by a Renault Espace and Romana was behind the wheel...

I think this thread sums up the problem of making time travel the core of the show rather than a tool to launch the stories. Basically, you can do whatever you want and then undo it all again with a wave of the Doctor's hand. RTD started it when he killed off a tenth of the worlds population only for it to never of happened. Where's the threat? Rory's dead but, yeah, he will be back again in a bit. Now he's REALLY dead. But actually not because he killed himself (again) to stop himself from dying. Now he is really really dead. Yeah? Who gives a damn anymore?