1) MARSIS IS going to be deployed. The current date for this is the end of May (although is overhead said April, so don't hold your breath!). However, they are still not completely sure that it will not malfunction, it seems to be a case of its worth the risk given the instruments potential.
By the way, for those of you that don't know the problem with MARSIS is that the antennae are folded up in a concertina like way but there is insufficient damping at the bends. Thus after it extends it will start to fold up again potentially hitting the spacecraft or even worse, wrapping around it!
Not good in any case.2) It appears that the MARSIS data (if we ever get any!) is going to be VERY difficult to process and may be impossible for some regions due to surface roughness, residual magnetic field and/or ionosphere. I got the impression that even after lots of modeling no one is really sure how well it's going to work.
JC