I don't think anyone mentioned the new shimano PD-A600 Ultegra SPD-SL Road pedals. These are new and I think you can get them from Amazon for about $86.00 they weigh about 285 grams per pair and have a true Road pedal type of platform which makes it very comfortable. They are a step up from the 520's and they are a very good pedal and still allow you walk around normally when its time to get off the bike.
Nice. Does look like a fancier version of the A520. Someone made a mistake in the copy for the Amazon listing and it is now spreading across the internets. Those are clearly SPD pedals, not SPD-SL. I can't find them on the Shimano site.