Sorry to bug you again, but I am completely unfamiliar with the Uranian/Jovian satellites (outside of Jupiter and Saturn). They should hold at least a few conspiracy-theory Zapruder Film-type clues. I noticed the article you cited only stated a "rocky" interior, surrounded by water ice and ammonia. No surprises there, but what is "rocky"? What holds a Jovian giant together?
Gravity holds 'em all together (whether rocky or gas giant or Pluton). Jupiter's satellites are much more numerous (60+) than we all learned in school, and many (most?) of them are in retrograde orbits, which is generally considered diagnostic of capture origin.
Jupiter's core?
http://www.freerepublic.com/focus/chat/1294934/posts?page=12#12
Oh, and from that same topic, there's also this:
http://www.freerepublic.com/focus/chat/1294934/posts?page=10#10