What's really sad is that this is old news.
If you dig through the Viking lander data, you will see that Viking had a test specifically for determining if there was life present in the martian soil.
The test involved scooping up some soil, and using a chemical sniffer to look for the by-products of metabolism - stuff like methane, amonia, oxygen, and CO2 coming off of the soil. Then, they heated the soil to something like 300 degrees C (which would kill the biological material), and then rechecked with the sniffer to see if the chemical signature was gone.
What did they find? The soil gave off methane before being heated (indicating biological metabolism), and no methane after being heated. The logical assumption is that there was life present, which gave off the methane, and the heat killed the lifeforms, so no metabolism was occuring afterwards.
What did NASA classify this as? A sensor anomaly, even though all of the self-diagnostics on the Viking lander checked out perfectly. Like I said, this is old news that has been ignored since the 70's.
Maybe this "new" news will prompt enough interest to fund a mission which actually brings back some soil samples.
BPRJam