I picked it up at Gen Con but, unfortunately, I've been pretty busy at work and school to have much time to really break it down (Christmas break is coming!!). Looking through it is a real pleasure, however. It is a beautiful looking full color book. All of the main characters have been statted out, as well as some npcs you will remember from the series and movie. There are also floor plans of several space ships, including Serenity of course. And a glossary in the back with some chinese smack talk.
It looks to be a attribute + Skill check for combat rolls. The unique thing (at least to me), is that attributes are not a hard score, but a number of dice. For example, strength would be 1d8+1 for a very strong guy, iirc, and a weak person may only be 1d4. So instead of having a modifier to your roll, you would actually roll the number of dice for that attribute.