Also due to popular demand we are releasing the source code for HD View SL, the Silverlight based viewer that is output by ICE and by the Photoshop Plugin. As this name indicates we are gradually migrating HD View, a Windows only browser plugin, to HD View SL, a cross-platform Silverlight Rich Internet Application. There are still some significant differences between HD View and HD View SL but we are confident that these differences will gradually disappear. For a detailed comparison of the two technologies please see the HD View SL CodePlex page.
If you are interested in Silverlight programming I encourage you to download the source and start making customizations to the viewer. Some customizations that I would love to see are different navigation UI, auto-scroll of the view, and keyboard short-cuts.