The current Razor 18x9s fit flush with the top of the fenders. I like that look. Doesn't look like the roller skate look at all. I am aware there is an offset floating around out there that DOES stick out beyond though.
However if you are a fan of the "stock 18s look" where the wheels are tucked in to the fenders by about an inch, then wait for the new Razors. Personally I don't like that look. Makes the car seem too big for it's wheels.
I like the flush fender look. Looks like an angry bulldog waiting to chew up the road.