I might also add http://www.space.com/scienceastronomy/070920_mars_tale.html
to the list.
Anyways, it's interesting, do we see water-related features on Mars because we want to see them, or because they really exist. It's one that the HiRISE team had been considering when I was still on the team, I always enjoyed talking with them about the latest advancements. I think to a certain extent we could say we really don't know anything, but, well... I'm sure the water/no water debate will be going on for some time to come, probably not until we have geologists on the ground there for an extended period of time can we make a surer judgement.