Easier perhaps, but there's even less reason to offer a CDMA alternative for that platform for a number of reasons. The first one is that the existing service plan available for it isn't tied to your (any) existing cell plan. Presumably having a CDMA board would mean other carriers would/could offer something similar, making the only advantage one of possible price competition for that data plan.

The iPad is more of a computer than pocketable communications device. Chances are you'll have (and want) WiFi where you'll be using it most. A lot of people are going to skip the 3G add-on. I'm not sure creating two different add-ons is going to bring double the upgrades.