I just saw this as well. It surprised me when I first found out that Sprint was mostly a "holding" company and outsourced most tasks to contracted companies. I wonder if this trend will continue with any other positions. Also, I'm assuming none of the design is handled by Ericcson, only the actual maintenance/running of it. This would imply that Ericsson was having issues running the nascent, rather small network of LTE sites currently up? Surprising to say the least.
EDIT - Also, I'm aware that AT&T contracts out the running of their network as well and that Verizon controls it in house. What do the other providers do? T-Mobile, Leap, etc.?