While ModalDialog is not default for editing list items in SharePoint 2013 Preview, there is a new “popup” element in SharePoint - callout or popover. I would like to recommend these two blogs when you want discover more: Andrey Markeev: Callouts (popovers) в SharePoint 2013 Preview (in Russian) Alex Boev: a three part series: 1. Custom Callouts in the SharePoint 2013 Metro UI: Part 1: Basics 2. Custom Callouts in the SharePoint 2013 Metro UI, Part 2: Actions 3.