In the second article is mentioned some work of Jakosky that current trends suggest that the southern CO2 ice cap could periodically melt entirely on the time scale of thousands of years.
And this article suggests this might raise Mars average atmospheric pressure from 6 mb up to 30 to 40 mb thereby allowing liquid water pools on Mars:

Once Upon a Water Planet
Today the Red Planet is dry and barren, but what about tomorrow? New data suggest that the long story of water on Mars isn't over yet.
"MOLA and MOC measured how the polar caps shrink in each hemisphere's summer. They shrink so much, in fact, that if the observed trends were continued for just a few centuries, nearly a third of each polar cap could evaporate into Mars's atmosphere. That would pump the atmospheric pressure up from 6 millibars to 30 or 40 mb (the Earth's atmospheric pressure is about 1000 mb) -- high enough pressure for liquid water to be stable on the planet's surface under certain temperature conditions. Thus, perhaps as recently as just a century or two ago, Mars might have been "clement enough for ponds of water" to have dotted its surface like desert oases, Garvin said -- and current trends suggest it might become so again."
http://science.nasa.gov/headlines/y2002/12mar_waterplanet.htm

Bob Clark