page item name property in UI

You have an opened document with page items?

try this:

app.activeDocument.layers[0].pageItems[0].name = "my Item #1";
app.activeDocument.layers[0].pageItems[0].selected = true;
app.redraw();
alert(app.activeDocument.layers[0].pageItems[0].name);

I don't have CS6, but yes, the name is what you see in the Layers palette...show you code and the layers palette expanded.