Not necessarily. Schiaparelli used hydrazine for fuel, and if it smashed into the surface it seems to me that it's a reasonable assumption that the whole crash site is contaminated with it. Is that something we want to get all over the rover?

Hydrazine is extremely unstable right? Would much of it remain after slamming in to the ground?

With a bit more Googling, it appears that hydrazine's lifetime in (Earth) atmosphere is measured in hours. I'm not sure what that would be on Mars, or if soaking into the soil there would increase its lifetime.

It's a fun mental exercise, I guess -- I'd love to hear from somebody in the field who knew more about hydrazine -- but as the Opportunity rover is still a long (likely impossible) distance away from the crash site, it will likely just remain a mental exercise.

Both are good answers... let's see what scientists decide. In te meantime, MRO should give some interesting hi-res pictures.

Yes! I wasn't aware that a second fly-over with a better imager was going to happen, but now I'm morbidly curious.

> ...how soon Opportunity could get there...

Months, to say the least -- the rover moves very slowly. Ever since it got to Mars, it's moved at about ~3,5 km/year (just shy over 2 miles/year). I think a more realistic estimate could be "longer than it has been there".