The NGST does a lot more pointing than a commsat but in many ways is no more complex, so it shouldn't be all that difficult to design it for a long life. They also have many years of HST operations to guide the NGST design. There are some things that are a lot easier out at L2 compared to LEO, such as the constant sunlight for steady electrical power and eliminating the thermal cycling that the HST experiences on each orbit.

The HST has had problems over the years with the reaction control wheels (similar to gyros) used for pointing but the situation should be a lot easier out at L2 because it can be pointed at a target and left there easier than if it were in LEO like the HST. Unlike the HST, the NGST will almost certainly have to have some form of propulsion system, if for no other reason than to unload the momentum from the reaction control wheels. The HST uses magnetic coils to interact with the Earth's magnetic field to accomplish that task.