the Hildon framework has been integrated into QT , cant speak for GTK as I dont know much but I would not think its different as Hildon is built on top of GTK, feel free to correct me Hildon gurus.

For the QT api's that have hildon features check out the wiki. here and here
It talkes about Kinetic scrolling, stackable windows, menus from the title bar etc.

so just start making your QT apps using some help from these wiki's and you will see it nicely working on the maemo platform.

hope that answers.