Perhaps it can also spot the European probe that presumably crashed (at one of the poles if I recall correctly) several years ago.
That would be the Beagle 2 lander that ESA launched in June, 2003 with the Mars Express orbiter. Beagle 2 landed on Christmas day in 2003, but was never heard from again. It was declared lost on February 6, 2004.
In December 2005, ESA announced Beagle 2 may have been spotted on the surface of Mars in enhanced, lower resolution images taken by the camera on NASA's Mars Global Surveyor orbiter. The likely location identified is in the vicinity where Beagle 2 was expected to land, Isidis Planitia, an ancient impact basin just north of the equatorial region on Mars.
You're right, Buck W., NASA believes MRO can spot Beagle 2 on the surface and a search has been placed in future work plans for the HiRISE camera.