Some of the Middleton areas are up and running. Some of the East Madison towers are upgraded, but the backhaul is not. Until the backhaul is complete, the towers will not be "turned on" (it is NOT worth turning on LTE for a backhaul that is already horribly oversubscribed at this point).
I've heard differing "rumors" on when the backhaul will be complete...anywhere from back in August through the beginning of next year. It's hard to predict the actual dates when it comes from multiple layers of contractors to do the work (backhaul owned by AT&T or Charter who contracts Bob, who contracts Jimmy, etc., etc.) LTE requires a solid backhaul to work, which is really where Sprint is struggling in certain areas...unfortunately, Madison is one of many of those areas. It's easier to trench holes and pull cables in smaller communities than it is in a developed city.