alfiansyah rahman has produced an icon set to make Maemo 5 look more like Harmattan (and Symbian Anna). The package is available in Extras-devel and, as it modifies core system files, some care should be taken.
Although there is a sample application on the N950 which allows the taking of screenshots, and the Ctrl-Shift-P technique from Maemo 5 continues, neither of these will work on the keyboardless N9. Sampo Savola has released a small application to fill the gap: I could not find good screenshot tool for Harmattan so one night I coded small qt-components application that will do the job. User can set the delay before the screenshot is taken.Screenshots will be saved to MyDocs and screenshots can be taken in both portrait and landscape orientation. Application will make the device vibrate when the screenshot is taken.