openlayers/ol3 — pull request #2756 by bartvde (2014-09-26 13:39:10+00:00)
Title: Add an example for using an Esri 512x512 tile server in EPSG:4326

This shows how to use http://services.arcgisonline.com/arcgis/rest/services/esri_imagery_world_2d/mapserver in ol3.

So currently XYZ sources can only be used with 256x256 right?