So maybe icecap melting is not technically irreversible...

But you have to read the small print! The cited article appeared under the byline Marlowe Hood, Agence France-Presse, Dec. 16, 2010. An acquaintance of mine seems to think (presumably based on the very misleading headline) that this means that climate change is no longer a concern. However, if you read the whole thing, you will find this paragraph (way down near the end of the article):

"But the study, based on computer models, indicates that if annual emissions of greenhouse gases are substantially reduced over the next two decades, an initial phase of rapid ice loss would be followed by a period of stability and, eventually, partial recovery." (my italics)

Since there seems to be an emerging consensus that there isn't a snowball's chance in h*** of substantially reducing GHGs ever (or at least while our species is still around in anything like our current numbers), let alone in the next few decades, the article is at best useless, and at worst positively misleading (especially if, like my acquaintance probably did, its readers saw the headline and stopped there).

"'But it's also an incentive for mitigating greenhouse gas emissions,' [University of Washington professor Cecilia Blitz, coauthor of the study] said in a statement." This at least is not actively misleading - even though it's basically whistling in the dark!

Full article (much copied over the last few days): "Arctic icecap safe from runaway melting: study".