Thanks for the link. The criticism that cosmic rays would have destroyed such life because ice would not provide much protection really is not valid since it has been known for some years now that comets are more dust and rock than ice. This has been further confirmed by the Deep Impact mission:

A large dust/ice ratio in the nucleus of comet 9P/Tempel 1.
Nature 437, 987-990 (13 October 2005)
"Comets spend most of their life in a low-temperature environment far from the Sun. They are therefore relatively unprocessed and maintain information about the formation conditions of the planetary system, but the structure and composition of their nuclei are poorly understood. Although in situ1 and remote2 measurements have derived the global properties of some cometary nuclei, little is known about their interiors. The Deep Impact mission3 shot a projectile into comet 9P/Tempel 1 in order to investigate its interior. Here we report the water vapour content (1.5 times 1032 water molecules or 4.5 times 106 kg) and the cross-section of the dust (330 km2 assuming an albedo of 0.1) created by the impact. The corresponding dust/ice mass ratio is probably larger than one, suggesting that comets are 'icy dirtballs' rather than 'dirty snowballs' as commonly believed4."
http://www.nature.com/nature/journal/v437/n7061/abs/nature04236.html

Also, in your link one scientist argued it has not been proven that comets exist in other systems. But there is plenty of suggestive evidence that they do:

NASA's Spitzer Finds Possible Comet Dust Around Dead Star
For Release: January 11, 2006
http://www.spitzer.caltech.edu/Media/releases/ssc2006-04/release.shtml

Comets Collide as Star System Dies?
Larry O'Hanlon, Discovery News
http://dsc.discovery.com/news/2007/02/14/comet_spa.html?category=space&guid=20070214143030

The Star-grazing Extrasolar Comets in the HD 100546 System.
THE ASTROPHYSICAL JOURNAL, 483:449–456, 1997 July 1
http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v483n1/35281/sc0.html

And the criticism of one scientist in your link that clay was not found in the Deep Impact mission "per se" is misleading at best:

Spitzer and Deep Impact Build Recipe for Comet Soup.
Published: 16:01 EST, September 07, 2005
"These solid ingredients include many standard comet components, such as silicates, or sand. And like any good recipe, there are also surprise ingredients, such as clay and chemicals in seashells called carbonates. These compounds were unexpected because they are thought to require liquid water to form."
"How did clay and carbonates form in frozen comets?" asked Lisse. "We don't know, but their presence may imply that the primordial solar system was thoroughly mixed together, allowing material formed near the Sun where water is liquid, and frozen material from out by Uranus and Neptune, to be included in the same body."
http://www.physorg.com/news6294.html

Bob Clark