The latest issue of Science has a fascinating article on Exotic Earths—it contains the results of simulations of planet formation in systems like those that have been observed with giant planets close to their stars. The nifty observation is that such simulations spawn lots of planets that are in a habitable zone and that are very water-rich.
Dynamics of Cats has a better summary than I could give, and it leads in with this lovely illustration of an hypothetical alien organism on one of these hot water worlds.
The only thing cooler than a cephalopod has to be a tentacled alien cephalopodoid. There’s a high-res version of that image at Dynamics of Cats—and I’ve got a new desktop picture.