As recent news stated Symbian ^4 will not be released but instead updates will be released for Symbian ^3 and the platform will evolve into what should have become Symbian ^4 at some point.
Also stated in the comments on conversations.nokia.com is that Orbit Ui (Ui Extensions for mobile) (Uiemo) has been discontinued in favour of native Qt and Qt Quick.
I don’t know what to think about this yet but at least there are not two competing Frameworks for Ui development anymore (Meego Touch Framework and Orbit).