- access the metadata declared in a widget's configuration document,
- receive events related to changes in the view state of a widget,
- determine the locale under which a widget is currently running,
- be notified of events relating to the widget being updated,
- invoke a widget to open a URL on the system's default browser,
- requests the user's attention in a device independent manner,
- and check if any additional APIs requested via the configuration document's feature element have successfully loaded.
This is somewhat related to MPEG's Rich Media User Interface Framework for which the Call for Proposals is open until April. Requirements for the this Rich Media UI Framework can be found here and some further information about this interesting exploration activity can be found here.