here's how i'd like it to play out, personally:
1. app store submitted widgets for notification centre. a widget is essentially a persistent and dynamically updating notification (on osx they can also perform utilities, but i'd argue that on a phone, as soon as it starts processing user input, its better suited to be an app anyway).
anyway, the precedent has been set with weather and stocks, if options expand, this is where they'll be found. nice to have: since other notifications can live on the lock screen, hopefully they'll let widgets go here too. also: i agree they really should show some sort of 'unread notification' symbol in the status bar.
2. live icons for home screens. make it live in the tasteful space between the more robust information that should be communicated through a widget in notification centre, and the rather limiting numeric badge option that currently exists.
i don't see apple letting a bunch of "because we can" spinning and glimmering animating icons for the sake of it, but an icon should be able to update its appearance in a more flexible way while still retaining a consistent format so the app remains recognizable.
like so many other features that eventually get opened up, apple already has this framework in place for themselves, as evidenced by the calendar app. and the omission of a dynamic clock reinforces my belief that they won't allow anything that would be updating nonstop (i.e. the second hand, or even potentially the minute hand). there would probably be strict requirements that updates occur at reasonable minimum intervals for automated updates, or by push.
3. as for the launcher thing, i really think it adds an extra step and essentially yet another modal region just to give you some sort of wigit-ified start page. my feeling is that we're better served by widgets on the lock screen/notification shade for when you quickly want to *see* something (and is consistently accessible no matter where you are), and keep the unlocked home screen of apps for when you want to *do*.