The date/time controls in the UI for Windows suite allow you to easily select dates and times with keyboard, mouse, and touch. By avoiding the calendar and selecting the date, month, and year separately it is quicker and easier for a user to select a date.
Thank you for the suggestion. I discussed it with our developers, and you'll probably agree that this type of UI visualization is specific for Windows 8/WP8 only. The standard HTM5 datetime input does not change drastically its appearance but rather have unified look and feel on all mobile platforms. That's why we decided to skip this feature. Note that you can still use Telerik UI for Windows 8 for the requested presentation on Win8/WP8 devices.