I gave it some thought, and I'd like to leave this as is. Consistency with the `Model#load()` signature would provide a minor convenience to a subset of implementers, but would be a weird signature to work with in virtually every other use case. I don't think it's worth it, especially when someone who wants to use a Model sync layer can just do something like:

```js
tree.plug(Y.Plugin.Tree.Lazy, {
    load: function (node, callback) {
        model.load({id: node.id}, callback);
    }
});
```