Not so fast, folks...
Could be that these are cosmic rays barelling through the CCD, rather than meteorites.
One suspicious thing is that the Pancam streaks are shorter than the navcam ones. If we were seeing a glowing meteor trail in the sky, they should be magnified more and be longer.
Dare say we'll hear more in due course, but it's pretty cool doing astronomy on another planet.
For your info, I'm off to LPSC in 8 1/2 hours time. I'll try to send in some posts about proceedings, if I get spare time!