Cassini has discovered that Titan's hydrocarbon lakes and seas do indeed change. Previous investigations have shown that Titan's liquid seas are motionless and that has always been a problem for the wind swept moon of Saturn. But now we know they change, probably due to warming in the atmosphere caused by the solar systems main power battery, the Sun.
How do we know? Well a big old island of something popped up in one of the lakes. We don't know what but we do know where. It could be an iceberg, receding liquid, methane bubbles causing waves. We just don't know yet.
We like Titan as a candicate for study because it has several earth-like features. It has an atmosphere and bodies of liquid that change and alter much like our own oceans. This makes the planet a candidate for life as we know it...well not really, but life under similar circumstances.
Hopefully Cassini can keep studying this and doesn't crash or the folks on Titan will have to cover it up and keep their own Rosewell from panicking the populace!