Don't worry about the cellular. Wifi is popping up everywhere in Negril. Lots of spots with really decent connections.

I noted a couple things while I was down there though in regards to television access on the iPad. Hulu, HBO Go and my Fios connections (in states, I can get about 90 channels on my iPad) did not work. Some international copyright issue.

Anything I downloaded from iTunes and the like were good to go however. That said, I should not be watching television down there anyway