Thanks for getting back to us.
Indeed, you have a point here that if the developer does not give a hint for the user that items can be reordered the user won't be able to guess by themselves. Although in similar scenarios it is normal to explain to your users what they can do on the current page, it might be useful in some special cases to be able to programmatically activate the reordering functionality.
We will make sure to enable this in Q3 2012.
Thanks for your feedback.
the Telerik team