I think Fusion applications design patterns (i.e. 'FUNCTIONAL' design patterns) are one of the most important resource to become publicly available as a result of Fusion apps development -
(They have been available in beta form for a while now and I made it a point to share with clients to help them create functional specificatinons)
New applications - even standalone plain ADF ones should especially leverage a lot of the learning and research that went into Fusion apps all these years.
As a former Fusion apps developer, it was only natural that I applied a lot of this learning in applications I developed elsewhere - but I had to be constantly mindful of not sharing any info that wasn't publicly available.