I'm currently reading "Unmasking Europa" by Richard Greenberg. It's a very interesting book which talks about the idea of the Europan ice crust being very thin, a few km at most, which goes against most established models which assume a layer of convective ice tens of kilometres thick, completely isolating the ocean from the surface. In the thin-ice model, there is a lot of contact between the surface and the liquid, leading to an oxygen-rich ocean capable of supporting complex life. In my opinion, Europa is the most interesting place in the solar system. Luckily, NASA is going to send a probe to the Jovian Moon around 2020. I wonder whether it will be possible to determine the thickness of the ice on that mission already, perhaps by including a small lander which probes the ice sheet with remote sensing equipment. Perhaps, if the thin-ice model is correct, we could land near fresh cracks and even look for frozen life forms. What technology would allow us to penetrate the ice and explore the ocean beneath? How near-term would it be?
NASA might launch a Europa orbiter in 2020; at this point it's just a proposal and it's up against serious competition.
It's depressing to think the last flagship was launched in 1997 and the next one will be at least 20 years after that, if ever...