Space.com has an article on last week's OPAG meeting in Boulder, Colorado. OPAG is a group set up by NASA to provide input on future outer planetary exploration. Among the mission concepts highlighted at the meeting was the Europa orbiter and a Titan blimp. Such missions may provide critical information on the geology and internal structure of both satellites. Unfortunately, I was not there in person (I could have been though thanks to the Io meeting shortly before it), but this gives a decent summary. Also discussed, from those who attended, was providing the capabilities on the Europa Orbiter to perform Io observations, but this would require a camera, which isn't guaranteed to be on the payload of EO.