It doesn't sound like it's a "done deal" based on Belize's history with these types of things (as Lan stated). And if it isn't, then the tourism community needs to actively voice their disapproval of this happening. Most Belizeans I've talked to about the cruiseship tourism that is already occuring did not like it at all. The only ones who did were employed by them. Hopefully, Belizeans will take it upon themselves to protest this "development."
The negative impacts of cruiseship tourism far outweigh the benefits for the host countries, as many people have already stated. If you don't believe it, do some research and read about the negative impacts of cruiseships already documented in other Caribbean locations.
There is no way ecotourism can co-exist with cruise-ship tourism on the scale this project is aimed at having.
Look at who is benefitting from cruiseship tourism already in Belize -- it's 2 large companies who control all of the day trips for the cruiseships (whose owners are already extremely wealthy). That's it! And those day trips only take tourists to the largest restaurants that can support large groups. It's not our favorite mom and pops that are going to benefit. In fact, they are going to suffer because Belize will be ruined for most of us who frequent those places.
Yep, I'll be looking out for the funeral for Belize's ecotourism industry and for Belize as we know it...