In the JavaScript API, there's FeatureLayer and LabelLayer classes. However, the LabelLayer class does not currently deal with conflict resolution of the labels. The labels need to be better associated with the graphics of the FeatureLayer, and supported by the same "conflict resolution" issues that face those graphics (ie., overlapping graphics). We ran into this when attempting to handle overlapping SimpleMarkerSymbols with labels. You could not tell which marker symbol the label was associated with. And in cases where part of the simple marker symbol was showing up, the label should have also shown up. Your samples lead us to handling this with icon marker symbols, but we're dealing with thousands of these with unique label values so the icon marker symbols won't cut it.
We also researched using SVG graphics to solve this problem but since we can only use a path element, we had no way to associate a marker and a text together. So possibly providing more capabilities with SVG graphics could help solve this problem.
