Sprint has been hot and cold with their relationship with Clearwire, the wholesale 4G broadband network that has been providing almost all of Sprint's 4G coverage. Sprint recently stated they will now start using their own network for 4G LTE coverage instead of Clear's WIMAX 4G network. That transition will probably will be slow to roll out. Sprint actually issued their own 4G Coverage Map which is identical to Clear's Map.
Sprint will will probably use as much of their legacy 1900MHz PCS spectrum as possible for their own flavor of 4G service, which is slightly better than Clear's higher, 2500MHz spectrum. Sprint's broadband will also reflect coverage more like their voice network, which may or may not cause problems for current users.
We can't help but think this situation will change again. Clear may convert to LTE, and Clear and Sprint may need each other strictly from an economic standpoint. Neither one of them can afford a new network, especially as an overlay, and there are other clouds on the horizon such as the potential failure of Lightsquared...or a potential competitor with the new Dish broadband network. Both events may force Clear and Sprint to play nice(r). After all, Sprint has invested lotsa Million$ in Clear that they probably can't get back.
As usual, nothing is certain and there's also always a chance of any one company not doing the smart thing. Would you be surprised if AT&T bought Clear? We expected Cricket and MetroPCS to tie up long ago. Just because they haven't doesn't mean it's still not the best course of action. The only Smart they may know, is their Smart Phones.