Great topic. Another interesting article:

Only Solar Systems With Jupiters May Harbor Life.

[A solar system with water-bearing asteroids but no giant planets might not evolve habitable worlds with oceans, they conclude.

The deuterium-to-hydrogen ratio in Earth's seawater is the key clue as to the source of the oceans. Seawater contains 150 ppm deuterium, or heavy hydrogen. That's about five or six times the deuterium-to-hydrogen ratio found in the sun and in the solar nebula gas, known from measurements made at Jupiter. But it's only about a third of the deuterium-to-hydrogen ratio measured in comets Halley, Hyakutake, and Hale-Bopp,. The findings contradict the popular idea that comets supplied the Earth with oceans.

"If deuterium abundances in the asteroid belt are correctly reflected by the meteorites, planetary embryos sent careening by Jupiter into the Earth are by far and away the biggest contribution to Earth's water,'" Lunine said.]

But, what about comets! :)

Ice survives on Mercury: <a href="http://nssdc.gsfc.nasa.gov/planetary/ice/ice_mercury.html";

Interesting systems in the making (old news to most of you here):

Formalhaut:http://www.space.com/scienceastronomy/new_planet_021010.html Apparently, Formalhaut is a binary system.

Zeta Leporishttp://www.solstation.com/stars2/zeta-lep.htm

Marcia