Gardian UK is 'seriously' considering it too.
Print is expensive to produce and distribute. Web based publishing is far cheaper. With tablets becoming ubiquitous, it doesn't make a lot of sense to continue to use pulp. Who (besides me) doesn't have a tablet?
Newsweek is betting on continued subscription revenue through their mobile distribution. I think that's a risky move. Between the covers of a Newsweek print magazine you've got nothing but Newsweek. Between the covers of a tablet, you've got every news and entertainment source in the world: there's no need to limit yourself to newsweek even at the subscription price of free.
What will you find in the dentist's waiting room?