With the last updates in Ubuntu 12.04 at least two new GUI in QT for existing applications are landed: Ubuntu One Control Panel, and Checkbox (the system testing tool). These new GUIs are pretty good, but they don't include the Ayatana scrollbars like the other GTK applications. I wonder if it is planned to apply the Ayatana scrollbars also for the QT GUI, or not. I mean, that these new GUIs are a good, but so far they introduce a bit of incoherence in the Unity Desktop experience. So far, we already have some applications, like Chromium or LibreOffice, that don't recognize the Ayatana scrollbars, but at least, all the rest of the GTK applications are coherent.
fossfreedom posted this as a comment, which essentially answers the question:
On its whiteboard (main page), that blueprint currently says:
But even now that it's January '13, there hasn't been much progress yet -- the status is still Not started and the direction is Needs approval.