I have a Samsung Fascinate and the rest of my family have Droids currently on Verizon, we have unlimited data, we don't have extra charges for data. Was there something more specific that you are wondering about being charged for?
do not be surprised in the least if they come up with a 2gig plan for the iPhone. Something fishy is going on--they explicitly state that data packages and pricing will follow soon. Why not just offer up the current crop if you weren't planning on changing anything? Regardless...I'd be shocked if they include their regular ol' unlimited data package.