I'd also like to add a request to the above feature request.
I had to implement this in Aware as a server side with Up/Down buttons and not client side with JS. The reason was that, every time an item would shift up or down, there is a sequence number (an attribute) that also needs to updated, so if the item was moved up, it's sequence number would reduced by one.
If Support decides to implement this feature, please be sure to give us the power to attach process to each direction movement, so we can re-sequence the items properly at the server side as well. Our grids are sorted by that important sequence number.
Thanks!