According to reports on the internets, the public areas of PlayStation Home will be region locked, so we won't be able to meet the French girl of our dreams bowling in Home. You will be able to invite foreign friends into your home, but you won't share the same public spaces and games.
Sony says this is to ensure that everyone gets an "experience most suited to their tastes." But it probably also has to do with region-specific advertising, marketing and media rights as well.
PS3Fanboy: Home will be region locked