Here's the real question.. Can you get it off without ruining the finish?
Yes. Pull off and wipe down w/ something mild like a damp paper towel and the finish looks brand new.
And as for the drop comment. It depends on how its dropped. If it hits flat it probably won't do anything. You have to hit some nasty concrete to tear the shield. If you hit on a corner it will probably tear it up as that is the weak area for a skin like this as far as protection.
So drop protection isn't bulleproof but scratch protection is exceptional. It also gives the phone a nice look and great grip.
I had this on my 2G iPhone and the metal case would be dented when hit really hard but the finish was perfect.
Honestly, I'm anal and have put about 10 of these on for myself, friends, and family. It takes a bit of practice to get it right where it is lined up, non bubbled, wrinkled, or other issues.
I've found the best way is to get a set of tight fitting latex gloves and then go at it. An iPhone installation should take about 45mins to do correctly and carefuly. Otherwise, you will get fingerprints under the shield and the finish will look 'off' from the oils in your hands.
I usually put soapy water in a bowl, put on the latex gloves and wash them with soap while on my hands, dip the skin in the water and begin application.
If installed right these are hard to beat and invisible...when not installed right they are useless and look bad.