BBC put out an article on the topic. They make it seem that ESA should probably pick one "Large" class mission (Laplace, Tandem, XEUS, Spica) and one "Medium" class mission (Cross-Scale, Marco Polo, Dune, Space, and Plato) by 2017 and 2018, respectively.
Obviously these missions are well down the pipeline and a number of things need to fall into place for these birds to get off the ground. Also, the "Large" missions are budgeted in the range of EUR650million, which is not enough to get a meaningful mission to the outer planets.
Thus, there needs to be some international collaboration. Whether NASA and ESA can pull off another Cassini-Huygens class success story remains to be seen, and as far as I can tell the international community hasn't decided whether Jupiter or Saturn is a higher priority. Hopefully this problem stimulates some constructive dialog.http://news.bbc.co.uk/2/hi/science/nature/7053057.stm