As is becoming increasingly clear there is no easy option available to non-US publishers. (I'm not sure there is an easy route for US publishers either, but at least they got to have a say in the drawing up of the Settlement.)Those publishers who do decide to opt out will have to do so by May 5. At the seminars it was announced that Google could start advertising a digitized book offer consumer service in the United States via the Google search engine as early as July.
Perhaps most bizarre is that all publishers must actively opt out, otherwise they will find themselves bound by the agreement. As publishers are finding out, there is almost no good reason to opt out, since Google could then carry on its digitisation process, and opting out would put the onus back on the individual publisher to pursue its own legal challenge—hardly advisable. Even objecting to the settlement at the Fairness Hearing, set for New York on 11th June, means you are bound by the agreement.
See also: The Digibooks Row