Fun with Lightning Data Service

ltngDataServiceFun.cmp

<aura:component >
	<aura:attribute name="recordIds"
                    type="List"
                    access="public"
                    description="An array of Ids"/>
    <aura:attribute name="records"
                    type="Map"
                    description="The records!"
                    default="{}"/>
    <aura:attribute name="errors"
                    type="Map"
                    description="The errors!"
                    default="{}"/>
    <aura:dependency resource="markup://force:recordPreview" />
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
    <lightning:button aura:id="logRecords"
                      label="Console.log records"
                      onclick="{!c.logRecords}" />
    {!v.body}
</aura:component>

ltngDataServiceFunController.js

({
	doInit : function(component, event, helper) {
		var recordIdList = component.get("v.recordIds");
		for(var i = 0; i < recordIdList.length; i++){
		    var nestedRecordString = "v.records." + recordIdList[i];
		    var nestedErrorString = "v.errors." + recordIdList[i];
		    $A.createComponent(
				"force:recordPreview",
				{
					"aura:id": recordIdList[i],
					"layoutType": "FULL",
					"recordId": recordIdList[i],
					"targetRecord": component.getReference(nestedRecordString),
					"targetError": component.getReference(nestedErrorString)
				},
				function(newRecordPreview, status, errorMessage){
					if (status === "SUCCESS") {
					var body = component.get("v.body");
					body.push(newRecordPreview);
					component.set("v.body", body);
					}
					else if (status === "INCOMPLETE") {
					console.log("No response from server or client is offline.")
					// Show offline error
					}
					else if (status === "ERROR") {
					console.log("Error: " + errorMessage);
					// Show error message
					}
				}
		    );
		}
	},
    
    logRecords: function(component, event, helper){
		var recordIdList = component.get("v.recordIds");
		for(var i = 0; i < recordIdList.length; i++){
			var nestedRecordString = "v.records." + recordIdList[i];
			console.log(component.get(nestedRecordString));
		}
    }
})

Lightning Data Service is only exposed in Lightning Experience and Salesforce1, so make sure that is where your component lives. https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/data_service_considerations.htm