Steve, that was my impression since those guys are accustomed to launching probes to even further targets such as Pluto (the new Horizon by the way used a slingshot boost using Jupiter's grav field to increase its speed).
Maybe it was due to the new technology with very large solar wings, which maybe raised some doubts about its efficiency.
It will be interesting to see the pictures taken from the Jupiter Cam in October.
Yes, Jupiter is a most weird and unhospitable world. Hydrogen-based extremely turbulent gaseous atmosphere transitions to metallic-hydrogen based ocean, where the gas phase and the liquid phase have no clear boundary. All soaked into a destructive radioactive and magnetic field... Maybe there is a solid rocky core, maybe there isn't, Jupiter should be able to confirm or deny such hypotheses.
The feature which impressed me most? The red spot, a colossal storm visible on its surface, has a size which can accomodate the radius of 2 or 3 earths!!