Not exactly what we had planned...

Maybe not what you had planned, but nicely executed.  The composition is right on, with the opossum looking into the photo.  It certainly has an intent look on its face.  I can't tell for sure at this size, but I wonder if it's as sharp as it could be around the eye and nose.  I suspect the camera was handheld to be able to react more quickly to a scene like this; if so, that may have reduced image sharpness.  The OOF dark object in the background on the left is a bit distracting, and you might consider cloning this away (if you're not adverse to such processing).  BTW, I worked as a biologist with a state agency, and I've heard these animals described as creatures that ooze from both ends when frightened, which is a very apt description based on the few that were brought into our office.

Stephen - 

I think your feedback is spot on. The eyes and nose should be sharper - I was shooting through both a screen and window (not the cleanest either), but I can't figure out whether that lack of sharpness (which is there in the full sized version) a focus issue or just elements between the lens and the subject. The camera was hand held, Nikon 105mm on a crop body with VR (and I was about 3 feet from the subject). Normally, this shoots very sharp when handheld. 

I am not averse to using PS to remove unwanted elements from the image - those darks areas to the far left and right certainly do call the eye.

...and thank you for the info on their behavior when captured...I'll make sure to steer very clear of them!

Mike