If you pass in tileInfo, the WebTiledLayer will use that. Otherwise, it defaults to web mercator.Edit: You already marked this as answered, but I wanted to follow up with more info and an example showing a non-web-mercator tiled layer.When you do this, your esri.Map will have to use 4326 as its spatial reference. This will happen automatically if you create your map and specify its extent in 4326 or if you specify no extent and the first layer you add to the map is your Google Imagery layer. I point out the spatial reference side of this because you won't be able to use other tiled services that are in web mercator. You'll still be able to use dynamic map services and feature layers as those support project on the fly.Here's an example of using a web tiled layer in 4326: http://jsfiddle.net/b2U82/