Maybe.
Scientists have found new evidence of small water flows on Mars as recently as five years ago, suggesting liquid water is trapped under the surface. This NPR article includes a photo of one of the flows in question.
Of course, everyone is already pestering them about what this could mean regarding life on Mars. The scientist in the first article is skeptical.
on Jul 12th, 2007 at 9:35 am
[...] it can probably exist just about anywhere. We’re already looking at potential water sources on Mars, but there’s a lot of stuff out beyond our solar system and I imagine the possibilities [...]