My understanding was that at least on the lock screen there was no easy way to distinguish between different calendars - I want birthday reminders to show up persistently for at least a week before the event, which is obviously undesirable for most other events.
If the lock screen gets/has that functionality, I'm not sure what the real difference between that and a widget is - except that mine displays on the home screen while yours displays on the lock screen.
And those things only work in cases where Apple has made special agreements. It's going to look silly when Facebook and Twitter are no longer things and iOS rushed to integrate them instead of just opening an API to enable it.
If the lock screen gets/has that functionality, I'm not sure what the real difference between that and a widget is - except that mine displays on the home screen while yours displays on the lock screen.