I recently posted a suggestion for this to Brainstorm:
viewtopic.php?f=83&t=142751
I figured generic functionality might be a good idea, but there's always a risk of over-engineering the thing so that it isn't really useful for any of the use cases. It seems that some applications, kdenlive and digikam being my favorites, would benefit from similar infrastructure. Thus, I figure it may be a viable option to develop it from the needs of these projects, but not go completely generic from the outset.