BEFORE you get the third, i highly recommend you play the first and second, as i am almost postive, you WILL be a bit lost in the GoW 3 Story..
and W00t, Mataki! I know her from the book! Great sniper.
Also, if the mulit is anything like the others, CHAINSAWZ arent the most effective method of killing opponents, go for SHOTGUNZ, look at GoW 2 vids to see what i mean
And i hope carmine lives THIS time...