If your laptop is wireless ready, they do have wireless, for a price of course. It is available in the atrium area on decks 3, 4 & 5, the Promanade Lounge, deck 9 and 10 and Studio Sea. There may be other locations, too, but those are the ones I remember hearing about.
There is also the internet cafe with computers for use, for again a price. That way if you don't want to carry the laptop with you, you still have access to the world wide web.
There is no internet access in the staterooms.