When will we able to label a feature service in ArcGIS Online? This is especially important now that Collector allows for disconnected editing. Since Collector cannot consume Map Services and it is only possible to label Map Services, this limits the data that will be available off line.
This idea has been merged with Collector - Label features.
In a normal AGOL map it also means that to label a feature service you need to also publish the map service and fool the map into thinking you have labeled the feature service.