While this new satellite system may promise 3G like speeds, the initial latency of a sat system really sucks. I know, I live in the boonies and have one.
Click a link, off it goes 23,000 miles in space, then back down to the real internet to query a site. The return is the same up and back. Forget skype, gaming or any other interactive use.
GoGo is real cell based 3G, and while it slows down over Utah or when GoGo is giving it away and everybody is on line, the lack of latency makes it appear fast. GoGo works on the LA to FL gulf routes and if they put in the ground links it should work in MEX and within 200 mi of the island chain. Going way out to sea satellite is unfortunately the only way, but the "want it now" pax will complain anyway.
OTOH, any internet is better than Oprah on Live TV or drawing smiley faces on the bald spot of the guy in front of you.