AutoHotkey Community

I think I've seen this feature in macs, but I'm not sure. When you drag and drop a file to a folder, if you keep the mouse button pressed, that folder opens in a window, so you can still drag the file to a subfolder and so on until you release the file to the final destination. Could this be achieved with Autohotkey?

No

I think the vista-explorer does it this way.

both vista and XP allow dragging a file to the left side "folder tree" of Windows Explorer and hover the mouse (with Lbutton still held) over a folder, it will show an indented list of subfolders.
In Vista, you can hover over the folder's icon, in xp you must hover over the [+] to the left fo the desired folder.

I don't believe that opening the new folder to view it in the right pane is supported, I could be wrong.