So in your opinion, do you think there may be some form of life on mars?
In my opinion, yes. Mars was warm enough and geologically active for long enough to provide protective and stable environments similar to the early Earth, where life obviously originated because... well, here we are talking to each other. I don't think it progressed very far, mind you. But the long chains of complex organics that have been found, and continue to be found, tell us that something was there. I don't think it was a lush forest world, or anything. But there's good evidence for the former existence of hot microbial baths, if nothing else.
Whatever was once alive, if it's still there anywhere, is going to be found in the brine washes, underground reservoirs, or in places like this polar Lake. You can't go anywhere wet on this planet without finding evidence of the life that's on it. These reservoirs, and perhaps wide-ranging hydraulic chambers, would be like time capsules from the early Martian world, storing samples of whatever there used to be. It's also deep enough that it should have been protected this whole time from the radiation that currently bathes the whole surface. (Just 3-5m down, I think you're fully protected.) This news is bigger than I think people are going to give it credit for.
The most intriguing line in this whole study comes from the full text @ Science:
http://science.sciencemag.org/.../07/24/science.aar7268.full
"The limited raw-data coverage of the SPLD (a few percent of the area of Planum Australe) and the large size required for a meltwater patch to be detectable by MARSIS (several kilometers in diameter and several tens of centimeters in thickness) limit the possibility of identifying small bodies of liquid water or the existence of any hydraulic connection between them.
Because of this, there is no reason to conclude that the presence of subsurface water on Mars is limited to a single location."
I say land a craft and start drilling.
I'm just as eager, but...
There's an ethics issue that we, as an exploratory species, have to confront soon.
If we do these experiments without using "clean" spacecraft and tools, we're going to be muddying the waters, literally and figuratively, of a possibly biologically viable or active alien environment. Whatever organisms or microorganisms might exist therein could be irreparably damaged in our pursuit of knowledge. I'm just as eager to land exploratory drills as the next guy (all over the Solar System!). But, like with Enceldaus and it's massive subsurface ocean and obvious geothermal activity, if we aren't careful, we could very quickly destroy these delicate natural habitats. And we'd be working with something we don't even remotely understand the chemistry or biology of. Killing off our alien neighbors, no matter how insignificant they might be, would be an utter failure on our part.