A microscopic image of the Alan Hill 84001 meteorite, which is the culprit for this discovery.

"Compelling new data that chemical and fossil evidence of ancient microbial life on Mars was carried to Earth in a Martian meteorite is being elevated to a higher plane by the same NASA team which made the initial discovery 13 years ago.

Now, 13 years after the Martian meteorite life story emerged, the science team finally feels vindicated. Their data shows the meteorite is no smoking gun but is full of evidence that supports the existence of life on the surface of Mars, or in subsurface water pools, early in the planet's history.

The new data are expected to be addressed publicly within days by NASA Headquarters in Washington, where they could become part of the political debate on future NASA mission directions."
via SpaceFlightNow

From David McKay's (only the most renowned astrobiologist in the world) latest paper: Origins of magnetite nanocrystals in Martian meteorite ALH84001, Geochimica et Cosmochimica Acta, Volume 73, Issue 21, 1 November 2009, Pages 6631-6677:

"We conclude that the vast majority of the nanocrystal magnetites present in the carbonate disks could not have formed by any of the currently proposed thermal decomposition scenarios. Instead, we find there is considerable evidence in support of an alternative allochthonous origin for the magnetite unrelated to any shock or thermal processing of the carbonates."

Word is, NASA are currently readying a press release that will be out in a few days' time.

Further reading:
Space Flight Now
Daily Mail
Above Top Secret