Here is more verbose code snippet for what I was doing successfully at beta update3...
protected function titlewindow1_creationCompleteHandler(event:FlexEvent):void
{
emLayerList.selectedIndices = selectedIndices;
emAssetLayer.getAllDetails(new AsyncResponder(onResult, onFault));
}
private function onResult(allDetailsResult:AllDetails, token:Object = null):void
{
_emLayerDetails=allDetailsResult.layersDetails;
_emLayerListDataProvider = new ArrayCollection;
for each (var o:Object in _emLayerDetails)
{
var item:Item = new Item;
item.layerID = o.id;
item.name = o.name;
if (o.geometryType == "esriGeometryPoint")
{
item.legendImage = o.drawingInfo.renderer.symbol.source;
}
_emLayerListDataProvider.addItem(item);
}
}