Sprint must not see enough of a market for that kind of device. And perhaps their customer base is too small for them to be able to economically purchase a world device for their network to supply whatever demand there is.
I think there are a lot of business customers with international needs. I see lots of people carrying Sprint BB Tours. Sprint has not launched an international smart phone in 2 years. The BB Tour is such a bad device in terms of dropped calls and call quality that I can't imagine there would be another reason to carry the phone other than international service. I don't think Sprint is intentionally telling their customers to go elsewhere because you travel and we don't want that kind of business. When wireless carriers consider the cost of adding each customer giving marketing expenses, advertising, support, phone subsidies, etc, they can't afford to lose customers over a device that already exists.
They must have plans to launch something. I hope it's android. Sprint does not offer the iphone or a touch screen BB. BB demand seems to be falling anyway. This is why I think android would be the obvious platform especially since CDMA already has one. It's not a matter of going to great expense to create something completely new and different.
I hope you are wrong, but who knows at this point.