While I really believe this is the future, I do have some questions. Although much can be miniaturized (nano-rized?), I'm wondering about some things such as optics (for cameras) and antenna/power (for transmitting the results back home). So while these may very well flutter down Saturn's atmosphere, there may need to be a large(r) mothership capable of transmitting the results home. (This was the mechanism used by Greg Bear in his novel "Queen of Angels" where his interstellar ship dropped "coin" sized probes to explore the worlds of Alpha Centauri.)
With the retirement of Endeavour we have the end of one technology coinciding with the birth of another.