It is true that United has announced plans to hire flight attendants in early 2006. All furloughed flight attendants that took a voluntary furlough have been recalled to work. It has been said that recruitment is expected to be in the United States, with new hires being based in San Francisco, Chicago, and Washington. This would mean that all recruits would have to be legal to work in the US.
As far as hiring outside of the US is concerned, United flight attendants based outside of the US are members of the US union the Association of Flight Attendants (AFA). The AFA contract does however allow for a certain number of 'regional' flight attendants that are not union members and not paid union wages, usually considerably lower. These f/a's wear different uniforms, cannot be mixed with union crews, and have to be furloughed before any union f/a. This was done shortly after the 9/11 attacks. Previous bases for 'regional' f/a's' were Singapore and Bangkok. It is expected that United would exercise the ability to hire 'regionals' now that all AFA flight attendants have been recalled, but, no plans for this have been officially announced.
This is the word from the US West Coast. Hopefully someone can add information and perspectives from those bases outside of the US.