With the rework of KNotifications I would like to move KStatusNotifierItem out of KNotifications. It is not really related and drags in additional dependencies.
I'm also proposing to investigate whether we need KStatusNotifierItem at all or QSystemTrayIcon can replace it. They both implement the FDO SNI protocol (albeit the situation is a bit complex since plasma-integration uses KSNI to implement QSTI) and QSTI promises better cross-platform support.
QSTI is missing some API that KSNI offers, but we should investigate what is really needed and implement that in Qt.
At Akademy @mart indicated that he supports this plan