Since I’ve been playing a round with Jinja a bit the last few days, I needed django-assets to support it as well. So it can now be used with both Django and Jinja templates, even simultaneously. So far, the code is only in bzr, not packaged up. Details in the Readme, though it’s all pretty straightforward.
I initially had some trouble porting the Django template tag to a Jinja extension, partly due a seemingly limited number of examples out there – so if you’re in the same boat, maybe this will help.