I will assume that you have looked at all 3 (yes, thats _3_) links in the header... which are links to far more detail than any person with a life really needs... so here is a brief (and only slightly demented) encapsulation.
These traces were 3.6 billion years old, when they were formed on Mars. They got to earth approximately 13,000 years ago (after a 16 million year journey). Since then they mostly (till very recently) sat in Antarctica .
If you have been paying attention (and I mean that last link to Antarctica, dammit!) you will have noticed that most of the photos were of frozen water... NO ROCKS. So any rocks on the surface of the ice are probably meteorites... it's ez to find em... that's one reason why scientists look for them in Antarctica, and they get a bonus because the weather preserves the meteorites very well.
If the research is indeed borne out, the following consequences immediately arise.
1) 3.6 billion years is only slightly (400 million years or so) later than the earliest traces of life that have been found on Earth. So life developed at roughly the same time on both planets. In that case, it is possible that life arose on one planet first and spread to other(s) through meteorite impacts. This speculation is perhaps buttressed by the similarity of certain microstructures in the meteorite to those created by organic action on earth.
2) (I'm reaching here...)If life existed on Mars and Earth (two places where liquid water existed), then why not on some other places in the Solar System..? Some of the satellites of Jupiter are known to have water on them, Europa (see also the NASA press release , pictures) and Ganymede; could they harbor life today...?
3)There is a famous paradox once enunciated by the physicist Enrico Fermi about the lack of communication from other intelligent species in the Universe... the paradox is now sharpened.(I dont really feel like going into the Drake equation , and probabilities.. email me, and I may or may not respond... alternatively, visit a library...)
This may be the most important discovery of the century with important philosophical and religious consequences as well.