Thanks to chaosman for pointing to this story down in the Robotic Space Exploration forum in the NASA Spinning Its Wheels Again thread.
According to this story, there are two independent measurements indicating a 10 ppb concentration of Methane in the Martian atmosphere, which, if true, would be a likely indicator of current life on the planet.
It cites both the European Mars Express probe, and some unnamed earthbased observatory as finding the evidence.
The Mars Express work was apparently done by Vittorio Formisano using the Fourrier IR spectrometer unit on the spacecraft.
The US work was done by Michael Mumma's team at NASA Goddard.
Here's a link to a more detailed story with other links.
Note that the current Mars Rovers have no tools to look for this stuff.
Forming opinions as we speak