The fundamental constraint in communications is called the "...sorry, you cannot view external links. To see them, please REGISTER or LOGIN probe launched in 1997, and landed in 2005.
Space probes are typically designed with the best space-rated components available 10 years before launch. So the electronics would have been selected about 1987. Space-rated components are typically about a decade behind commercial components in capacity and processing power, ie equivalent to PCs you could buy around 1977. In the intervening 36 years, PC power has increased by a factor of around 218 times, or around 250,000 times. Things like HDTV videos on commercial PCs that we take for granted in 2013 require far more storage and processing power than was available on Huygens/Cassini.More recent space missions like the Curiosity rover on Mars provide much better quality stereo images, because it is able to take advantage of many years of developments in electronics technology, the ability to provide a stable base for aiming a directional antenna, and a big power boost from carrying a large thermoelectric generator. Like Huygens, it is also able to take advantage of data relay via orbiting spacecraft.