Crazy bacteria and terraforming

What is the status of bacteria that live in extreme environments and their potential to terraform mars? Is there any program that is changing bacteria to eat martian rock and excrete oxygen and make a better atmosphere for humans? It seems that the earlier we start, the earlier we finish.

Present surface climate conditions on Mars make bacterial terraforming problematic at best. The only bacteria that can survive anywhere near Mars surface are the edndolithic (rockdwelling) bacteria, of which there is plenty if anomalius methane consentrations are anything to go by. To have a sufficiently robust biosphere that can alter Mars atmosphere you'd need plenty of liquid water and some nutrients + energy imput. Unfortunately Mars is in the middle of Dry Ice Age right now. Figuring out how to kick start a global warming on Mars is the priority for any serious terraforming attempt. Personally I favour hitting the south pole ice sheet with a methane rich comet if only because its the cheapest way to do it... not to mention that the fireworks are going to be spectacular.