Leave it at home. You can't get internet connection in staterooms (you can go to internet cafe if you absolutely must get online). Ship to shore phone connections are about $9.50/min. I couldn't imagine wanting to take my laptop on a cruise....I spend so much time working on them, that it seems like taking it with me won't let me "get away from it all".
We are thinking about taking our laptop like the above mentioned to empty the memory cards but to also have DVD access just in case the kids want to watch a movie in their room (other than what they show in-house).