No, NASA is not stating that we have found Mars Polar Lander. Mike Malin is an investigator on the Mars Global Surveyor mission, and the builder of the Mars Orbiter Camera used on that spacecraft. Malin has been analyzing images that were originally acquired by MGS several years ago. Malin has identified features on the surface of Mars that are consistent with the possible impact location of the Mars Polar Lander spacecraft. However - and we need to be very clear about this - all that is being said is that this is a POSSIBLE location of MPL. Some of the observed surface features fit one of the models that have been developed to explain how the spacecraft may have come to rest on Mars. However, this is not definitive proof. There is not enough information or detail available from these images to definitively state that the spacecraft has been located.
It is also important to note that NASA is not actively searching for MPL. As noted, this report is based on the analysis of images that are years old. In the course of ongoing science observations, some sites are observed that are also of interest for other reasons (such as the landing sites of various spacecraft). At this point in time, NASA is not planning to conduct a detailed survey of any spacecraft landing with the existing orbiters. However, these sites may be put on the planned observation list for the Mars Reconnaissance Orbiter, which will have a much higher resolution camera on board. MRO is scheduled for launch in August, 2005, and arrival at Mars in 2006.
You can see the original announcement from Malin
here.
-dave