ESA’s Rosetta/Philae mission has not only reached its destination, but Philae has landed. The landing seems to have been bumpy, but semi-successful.
For our purposes, the most important information is some useful detail on the makeup and looks of a comet.
From what I understand, the Philae launcher bounced twice because the ground was much softer than anticipated.
I think that besides the microgravity, one of the most noticeable features of the landscape would be the impossibly large overhangs from the very irregular shape of the comet. There is also outgassing and loose rocks everywhere. From what is being reported, the surface is solid with perhaps 10-12cm dust. In reality, the images of the comet are enhanced; the color of the comet is described as being “the color of charcoal”, so a character standing on the comet won’t be able to make out distant features and indeed may have trouble navigating without aid. (For a space opera setting like Contact Light, it probably makes sense to simply stick with a more traditional cometary image, that is, icy and white/gray.)
There are organic molecules present, which may or may not be a reason to go there.
Update: Surface, color.
Update 2: The BBC reports on additional features of the comet.