NASA released its finding today, "Mars is not a Dead Planet"

The first definitive detection of Methane in the atmosphere of Mars indicates that Mars is still alive, in either a biologic or geologic sense, according to a team of NASA and university scientists.
The discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," says lead author Michael Mumma of NASA's Goddard Space Flight Center. "At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif."

http://science.nasa.gov/headlines/y2009/15jan_marsmethane.htm?list111547

Most UK newspapers headlined NASA's findings.

http://www.thesun.co.uk/sol/homepage/news/article2133475.ece

It seems The Sun finds "the Life on Mars Story" rather important.
For the second day, its running a continuation of this story.

The next NASA Rover is not due to land on Mars until 2011,
while the British/Euro Rover, is'nt scheduled to land until 2015

URL with NASA Video to watch
http://www.thesun.co.uk/sol/homepage/news/article2137842.ece?OTC-RSS&ATTR=News

Looks promising, doesn't it! Life could be found, or proof that was life once present. Either way, it would be a milestone in human knowledge, and great boost to the search for Earthlike planets and SETI. And what if it turned out to be a DNA lifeform? And what if it didn't?!

Can methane ever come from a non-biological origin?

Yes, it can, and does.

I found this very informative: http://www.universetoday.com/2009/01/15/large-quantities-of-methane-being-replenished-on-mars/