Vista - ListView / TreeView, multiple selection and drag/drop

Hello,

I´ve tried to implement a drag on a Listview with multiple selected items.
For a single item its only handling MouseDown/Mouseup and MouseMove.
For multiple selected items, its checking if item under mouse is selected or
not. If selected deselect of the other items must be delayed until mouseup
and canceled if a drag happend. More logic is needed to check for
shift/control select.

My first question to get this working is, how can I get the listbox item
under the mouse ?

Generell question to the development team:
Are there any plans to simplify this often needed, anoying task on the
control side with a counterport to the drop functions like CanDrag, StartDrag
with returning IDataObject, AllowedEffects, visual feedback and DragDone with
final effect ? Please think about a buildin abstraction of drag not only
drop.