It's a nice ide - so nice that we do it already :-)
There's a CSS hack for it; as well as the interwiki link, you use {{Link FA|xx}} which gives an interwiki with a little star. It's not perfect - it needs manual maintenance - but it works well enough...
See, for example, http://en.wikipedia.org/wiki/Moon - half a dozen of the interwiki links are FAs.
It's a tiny little star in place of the bullet point. If I wasn't looking for it, I would never notice it. How about a full size star after the link?