Cre.ations.net's Nate True wrote a blog post describing what he found inside the iPhone firmware 1.1.3 update. Whilst digging around in the iPhone's firmware innards, he found that Apple has made some startling changes to the iPhone's OS, including:
The SpringBoard doesn't have to be modified to show custom Applications installed on the iPhone
Applications no longer run as root, instead they run as 'mobile'
Preferences are no longer stored in /var/root
True states additionally that he has also found what appears to be widget support in the SpringBoard.app. 'SBWidgetApplication' manages package locations and icons. So, what does this all mean? It might mean that the stars are aligning so properly that this might be the release: the one that makes it possible for 3rd party developers.